<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:019e7032-b3c7-7e2f-9f15-246316a9b347,g:2aecf03a-fce0-49c5-81cd-45032d6911e1-->
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:ck0000100334="http://www.americancentury.com/20260430" xmlns:xbrli="http://www.xbrl.org/2003/instance" xmlns:dtr-types="http://www.xbrl.org/dtr/type/2024-01-31" attributeFormDefault="unqualified" elementFormDefault="qualified" targetNamespace="http://www.americancentury.com/20260430">
  <xs:import namespace="http://www.xbrl.org/2003/instance" schemaLocation="http://www.xbrl.org/2003/xbrl-instance-2003-12-31.xsd"/>
  <xs:import namespace="http://www.xbrl.org/2003/linkbase" schemaLocation="http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd"/>
  <xs:import namespace="http://www.xbrl.org/dtr/type/2024-01-31" schemaLocation="https://www.xbrl.org/dtr/type/2024-01-31/types.xsd"/>
  <xs:import namespace="http://xbrl.sec.gov/oef-sr/2026" schemaLocation="https://xbrl.sec.gov/oef/2026/oef-sr-2026.xsd"/>
  <xs:annotation>
    <xs:appinfo>
      <link:linkbaseRef xmlns:xlink="http://www.w3.org/1999/xlink" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="ck0000100334-20260430_pre.xml" xlink:role="http://www.xbrl.org/2003/role/presentationLinkbaseRef" xlink:type="simple"/>
      <link:linkbaseRef xmlns:xlink="http://www.w3.org/1999/xlink" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="ck0000100334-20260430_def.xml" xlink:role="http://www.xbrl.org/2003/role/definitionLinkbaseRef" xlink:type="simple"/>
      <link:linkbaseRef xmlns:xlink="http://www.w3.org/1999/xlink" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="ck0000100334-20260430_lab.xml" xlink:role="http://www.xbrl.org/2003/role/labelLinkbaseRef" xlink:type="simple"/>
    </xs:appinfo>
  </xs:annotation>
  <xs:element id="ck0000100334_C000017045Member" abstract="true" name="C000017045Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_U.S.TreasurySecuritiesMember" abstract="true" name="U.S.TreasurySecuritiesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_U.S.GovernmentAgencyMortgageBackedSecuritiesMember" abstract="true" name="U.S.GovernmentAgencyMortgageBackedSecuritiesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_ConvertiblePreferredSecuritiesMember" abstract="true" name="ConvertiblePreferredSecuritiesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_SovereignGovernmentsAndAgenciesMember" abstract="true" name="SovereignGovernmentsAndAgenciesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_CommercialMortgageBackedSecurityMember" abstract="true" name="CommercialMortgageBackedSecurityMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_PreferredSecuritiesMember" abstract="true" name="PreferredSecuritiesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_MunicipalSecuritiesMember" abstract="true" name="MunicipalSecuritiesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_ExchangeTradedFundMember" abstract="true" name="ExchangeTradedFundMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_CollateralizedLoanObligationMember" abstract="true" name="CollateralizedLoanObligationMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_U.S.GovernmentAgencySecuritiesMember" abstract="true" name="U.S.GovernmentAgencySecuritiesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_ShortTermInvestmentMember" abstract="true" name="ShortTermInvestmentMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_OtherAssetsAndLiabilitiesMember" abstract="true" name="OtherAssetsAndLiabilitiesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000017047Member" abstract="true" name="C000017047Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000189734Member" abstract="true" name="C000189734Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000017101Member" abstract="true" name="C000017101Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_SemiconductorsAndSemiconductorEquipmentMember" abstract="true" name="SemiconductorsAndSemiconductorEquipmentMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_SoftwareMember" abstract="true" name="SoftwareMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_InteractiveMediaAndServicesMember" abstract="true" name="InteractiveMediaAndServicesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_TechnologyHardwareStorageAndPeripheralsMember" abstract="true" name="TechnologyHardwareStorageAndPeripheralsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_BroadlineRetailMember" abstract="true" name="BroadlineRetailMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000017103Member" abstract="true" name="C000017103Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000189744Member" abstract="true" name="C000189744Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000017102Member" abstract="true" name="C000017102Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000088050Member" abstract="true" name="C000088050Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000017105Member" abstract="true" name="C000017105Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000189743Member" abstract="true" name="C000189743Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000131599Member" abstract="true" name="C000131599Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000236113Member" abstract="true" name="C000236113Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000017106Member" abstract="true" name="C000017106Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_HotelsRestaurantsAndLeisureMember" abstract="true" name="HotelsRestaurantsAndLeisureMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_AerospaceAndDefenseMember" abstract="true" name="AerospaceAndDefenseMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_BiotechnologyMember" abstract="true" name="BiotechnologyMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000017108Member" abstract="true" name="C000017108Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000189746Member" abstract="true" name="C000189746Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000017107Member" abstract="true" name="C000017107Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000017109Member" abstract="true" name="C000017109Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000055524Member" abstract="true" name="C000055524Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000189745Member" abstract="true" name="C000189745Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000129042Member" abstract="true" name="C000129042Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000236114Member" abstract="true" name="C000236114Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000017094Member" abstract="true" name="C000017094Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_CapitalMarketsMember" abstract="true" name="CapitalMarketsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000017095Member" abstract="true" name="C000017095Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000189742Member" abstract="true" name="C000189742Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000017096Member" abstract="true" name="C000017096Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000017098Member" abstract="true" name="C000017098Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000017099Member" abstract="true" name="C000017099Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000189741Member" abstract="true" name="C000189741Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000212514Member" abstract="true" name="C000212514Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000212513Member" abstract="true" name="C000212513Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000017053Member" abstract="true" name="C000017053Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000017055Member" abstract="true" name="C000017055Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000189738Member" abstract="true" name="C000189738Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000017054Member" abstract="true" name="C000017054Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000017058Member" abstract="true" name="C000017058Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000017059Member" abstract="true" name="C000017059Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000189737Member" abstract="true" name="C000189737Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000131597Member" abstract="true" name="C000131597Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000247666Member" abstract="true" name="C000247666Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000017049Member" abstract="true" name="C000017049Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_ElectronicEquipmentInstrumentsAndComponentsMember" abstract="true" name="ElectronicEquipmentInstrumentsAndComponentsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_HealthCareProvidersAndServicesMember" abstract="true" name="HealthCareProvidersAndServicesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000017048Member" abstract="true" name="C000017048Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000189736Member" abstract="true" name="C000189736Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000017050Member" abstract="true" name="C000017050Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000017052Member" abstract="true" name="C000017052Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000055516Member" abstract="true" name="C000055516Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000189735Member" abstract="true" name="C000189735Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000131596Member" abstract="true" name="C000131596Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000212512Member" abstract="true" name="C000212512Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000017060Member" abstract="true" name="C000017060Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000017062Member" abstract="true" name="C000017062Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000189740Member" abstract="true" name="C000189740Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000017061Member" abstract="true" name="C000017061Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000017063Member" abstract="true" name="C000017063Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000017064Member" abstract="true" name="C000017064Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000189739Member" abstract="true" name="C000189739Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000131598Member" abstract="true" name="C000131598Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0000100334_C000214991Member" abstract="true" name="C000214991Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
</xs:schema>
