<SEC-DOCUMENT>0000845877-18-000128.txt : 20180529
<SEC-HEADER>0000845877-18-000128.hdr.sgml : 20180529
<ACCEPTANCE-DATETIME>20180529172756
ACCESSION NUMBER:		0000845877-18-000128
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20180524
FILED AS OF DATE:		20180529
DATE AS OF CHANGE:		20180529

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Grote Charles D
		CENTRAL INDEX KEY:			0001739712

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-14951
		FILM NUMBER:		18865668

	MAIL ADDRESS:	
		STREET 1:		C/O FARMER MAC, 1999 K STREET NW
		STREET 2:		FOURTH FL
		CITY:			WASHINGTON
		STATE:			DC
		ZIP:			20006

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			FEDERAL AGRICULTURAL MORTGAGE CORP
		CENTRAL INDEX KEY:			0000845877
		STANDARD INDUSTRIAL CLASSIFICATION:	FEDERAL & FEDERALLY-SPONSORED CREDIT AGENCIES [6111]
		IRS NUMBER:				521578738
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		1999 K STREET NW,
		STREET 2:		4TH FLOOR
		CITY:			WASHINGTON
		STATE:			DC
		ZIP:			20006
		BUSINESS PHONE:		2028727700

	MAIL ADDRESS:	
		STREET 1:		1999 K STREET NW,
		STREET 2:		4TH FLOOR
		CITY:			WASHINGTON
		STATE:			DC
		ZIP:			20006
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_152762926346739.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2018-05-24</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000845877</issuerCik>
        <issuerName>FEDERAL AGRICULTURAL MORTGAGE CORP</issuerName>
        <issuerTradingSymbol>AGM</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001739712</rptOwnerCik>
            <rptOwnerName>Grote Charles D</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O FARMER MAC, 1999 K STREET NW</rptOwnerStreet1>
            <rptOwnerStreet2>FOURTH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>WASHINGTON</rptOwnerCity>
            <rptOwnerState>DC</rptOwnerState>
            <rptOwnerZipCode>20006</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>SVP Finance and Investor Rel</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class C Non-Voting Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2018-05-24</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1667</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>32.39</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>7043.39</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class C Non-Voting Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2018-05-29</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>490</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>92.68</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>6553.39</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class C Non-Voting Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2018-05-29</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>582</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>92.68</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5971.39</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Appreciation Right</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>32.39</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2018-05-24</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1667</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>32.39</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2018-03-31</value>
                <footnoteId id="F4"/>
            </exerciseDate>
            <expirationDate>
                <value>2025-04-01</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class C Non-Voting Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>1667.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Transaction effected during an open trading window for employees and directors of the Federal Agricultural Mortgage Corporation (&quot;Farmer Mac&quot;).</footnote>
        <footnote id="F2">In connection with the net share settlement of the exercise of 1,667 vested stock appreciation rights (&quot;SARs&quot;) granted in April 2015 with a grant price of $32.39 per share, Mr. Grote was entitled to receive 1,085 shares of Farmer Mac Class C Non-Voting Common Stock. None of these shares were sold, as Mr. Grote retained 595 shares, and Farmer Mac retained 490 shares to satisfy tax withholding requirements arising from the exercise. The 582 shares reported as a disposition to the issuer of issuer equity securities represents the difference between the number of SARs exercised and the number of shares issuable as a result of the exercise. Each SAR represents the right to receive, upon exercise, the number of shares of Farmer Mac's Class C Non-Voting Common Stock equal to the excess of the fair market value of shares on the exercise date over the grant price.</footnote>
        <footnote id="F3">Includes 3,635 shares of unvested restricted stock previously granted pursuant to Farmer Mac's Amended and Restated 2008 Omnibus Incentive Plan. The grants of restricted stock have been described in detail in Farmer Mac's prior filings with the Securities and Exchange Commission.</footnote>
        <footnote id="F4">Exercisable beginning March 31, 2016 with respect to 1,666 shares, beginning March 31, 2017 with respect to 1,667 shares, and beginning March 31, 2018 with respect to 1,667 shares.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Anjali Desai, as attorney-in-fact for Charles D.  Grote</signatureName>
        <signatureDate>2018-05-29</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
