It ’s relatively rough-cut for aU.S. presidentto get involved in some sort of investigation during or after their stint in the Oval Office . The nature of that involvement and the type of investigation have varied wide over the year .

In 1807 , for model , Thomas Jeffersonturned over documents afterdeclining a subpoenasoliciting his testimony atAaron Burr ’s treason trial ; Ulysses S. Grant , on the other hired man , oncevoluntarily testifiedas a defense witness during a criminal trial against his personal secretary .

In other case — like Bill Clinton’s — the sitting President of the United States has n’t just been on the outer boundary of an investigation . Jimmy Carteris another good example : He testified during a 1979special counsel probeinto the fiscal dealings of his crime syndicate peanut byplay ( nothing incriminate was unearthed ) . There are also a number of time where President have complied with or denied call for evidence [ PDF ] . During theWatergatefiasco , Richard Nixondid both .

White House portraits of Abraham Lincoln (by William F. Cogswel), Harry Truman (by Greta Kempton), and Theodore Roosevelt (by John Singer Sargent).

Many congressional inquiries have featured presidential testimony , too — often , but not always , after a president has left theWhite House . They have n’t all been examining a past president ’s ( or anyone ’s ) actions for potential criminality ; passably oft , a chairwoman would show up to guard or oppose a part of legislation or offer advice on a congressional course of natural process . Below are nine U.S. presidents who have — subpoenaed or not — appeared before a congressional committee in soul for one reason or another ( and one who refused a process ) .

1. and 2. John Quincy Adams and John Tyler

In 1846 , Pennsylvania congresswoman C.J. IngersollaccusedMassachusetts senatorDaniel Websterof misappropriating money from the Presidential Secret Service Fund when Webster was secretary of state from 1841 to 1843 . Then - PresidentJames Polkagreed to bring out the amounts spent during that full point , but he would n’t disclose how the money was actually used . The fund was intend for espionage and other secret surgical process involving international affairs , and Polkfeltit was n’t his property to publicize information that the premature president had kept class . So the Houseset uptwo investigatory committees that then subpoena the former chairwoman , John Tyler , who testified that all of Webster ’s expenditures had been above board .

It ’s been reported thatJohn Quincy Adamswas also subpoenaed , prompting him to relegate a written deposition with item on how the fund had been used during his own presidency in the 1820s [ PDF ] . But even if neither commission delivered Adams an prescribed summons — or solicited intel specifically from his presidential tenure — he definitely was involved in the investigation . At the sentence , Adams himself was a member of the House of Representatives ( serving Massachusetts ) , and his stint aschairof the House ’s foreign affairs citizens committee had overlap with Webster ’s secretaryship . Adamsdidn’t timid awayfrom speaking up during House meetings on Ingersoll ’s allegement .

3. Abraham Lincoln

In December 1861,TheNew York Heraldpublishedparts of a words that then - PresidentAbraham Lincolnwas slate to deliver to Congress . The House Judiciary Committee identified valet - about - townHenry Wikoffas the leaker , but how he ’d come by the manner of speaking was a slimly dicier subject . Generally catch as an unscrupulous rogue , Wikoff boasted a close friendship with Mary Todd Lincoln , who ’d taken him on as a societal advisor of sort . It seemed most potential that she ’d given him the document — an idea reinforced by theunsubstantiatedbut not rare opinion that sheharbored Confederate fellow feeling .

In the close , White House gardener John Watt ( another Quaker of Mary ’s with abad reputation ) copped tofinding the speechin the library and reiterate what he remembered from it to Wikoff . The committee reportedly accepted this story in part because the Chief Executive himself showed up to prove on his wife ’s behalf , though details of his appearance remain unclear . concord to effectual scholar Ronald Rotunda , the hearing ms “ are equivocal on the question of Lincoln ’s presence ” at all [ PDF ] , but it was reported in a issue of newspaper at the metre .

4. Theodore Roosevelt

In 1911 , the Houseestablisheda committee to investigate U.S. Steel ’s 1907 leverage of the Tennessee Coal and Iron Company as a possible rift of the Sherman Anti - Trust Act of 1890 . Not only hadTheodore Rooseveltbeen president then , but he ’d approved the sale — and he gamely show at a commission hearing to justify why .

When the committee chairmanthankedRoosevelt for his “ kindness in come along … and answering so amply and completely every question , ” Roosevelt reply that “ an ex - President is merely a citizen of the United States , like any other citizen , and it is his plain responsibility to try and help this committee or respond to its invitation , just as anyone else would respond . ”

With that attitude , it ’s no surprise that Roosevelt again volunteered to testify the very next year , this time before a Senate subcommittee regarding fundraising ventures during his own 1904 reelection campaign . Rooseveltdeniedpersonally solicit money from corporations and stressed that any such donations came with no strings attach and held no sway over his legal action as president .

portraits of john quincy adams and john tyler

5. William Howard Taft

Roosevelt ’s successortestifiedin front of various congressional citizens committee more than a dozen times after leaving function in 1913 . The first was in January 1915 , when heappearedbefore the Senate Committee on the Philippines to fence against U.S. acknowledgement of Philippine independency . ( His plea failed to prevent the passage of the 1916Jones Act , which stated the U.S. would forgo sovereignty “ as shortly as a stable government can be established therein . ” It did n’t reallyrelinquish sovereigntyuntil after World War II . )

A couple other congressional affair thatTaftshowed up to weigh in on post - presidentship included the need to establish a national budget scheme and the need to relocate the Supreme Court from Capitol Hill to its own premises ( both finally successful endeavors ) . Many of Taft ’s congressionaltestimonieswere given in his capacity as Chief Justice of the Supreme Court , a position heheldfrom 1921 to 1930 .

6. Woodrow Wilson

Woodrow Wilsonwas still in office inAugust 1919when he tried to convince the Senate Foreign Relations Committee that the Senate should ratify the Treaty of Versailles . “ Every element of normal life amongst us depends upon and awaits the confirmation of the treaty of peace , ” hesaidin his opening remarks , followedby a 3.5 - hour question - and - answer seance . Wilson did at least come after in getting the Senate tovoteon the treaty — which they did twice , in November 1919 and March 1920 — but it was rejected both times , in part because Wilson was soresistantto amend it .

7. Herbert Hoover

Herbert Hoover’slist of congressional committee appearances is even longer than Taft ’s . Itstartsin December 1941 , when he was invited to advise the Senate Committee on Banking and Currency on the Emergency Price Control Act . Hoover hadheaded upthe U.S. Food Administration during World War I , so he had first - paw experience in conserve resource throughout a global crisis . At the committee hearing , the former president not onlyarguedthat “ price controls are dead imperative to pull ahead the war , ” but he also enumerated 14 ways in which lawmaker should transfer their focus from price mastery to “ commodity restraint ” for protect the national economy . In previous January 1942 , President Franklin D. Rooseveltsignedthe number into law .

AfterHarry Trumansucceeded Roosevelt in 1945 , heaskedHoover to call in the White House “ to talk over the European intellectual nourishment situation ” and eventually ended up sending him to more than three twelve nations to evaluate how the U.S. could help them avoid famine in the aftermath of World War II . William Hoover thenchairedtwo separate so - called “ Hoover Commissions ” that modernize the executive branch to “ promote thriftiness , efficiency , and improved avail . ” Throughout ( and beyond ) the Truman administration , it was n’t that uncommon for Hoover to show up at a congressional hearing to talk over his notion on those and other matters .

8. Harry S. Truman

Trumantestifiedbefore congressional committees several times after leaving the Oval Office as well . During a recap of the U.S. ’s United Nations charter in April 1955 , headvisedthe Senate Foreign Relations Committee to “ be everlastingly careful not to throw away the good and great instrument we already have in a lookup for something better , ” though he did admit that the U.N. had room for melioration . In subsequent show between 1957 and 1959 , Truman advise unselfishness in apportioning strange aid , backed a $ 5 billion tax cut of meat for low- and middle - income demographic , and recommended the annulment of the 22nd Amendment ( which prohibit prexy from serving more than twofour - twelvemonth terminus ) .

But Truman is better recollect for his one refusal to testify . In November 1953 , the House Un - American Activities Committeesubpoenaedthe former president over the U.S. attorney general ’s accusation that Truman knew Harry Dexter White was a spy for the Soviet Union ( still a factious claim ) when White wasappointedas the International Monetary Fund ’s U.S. executive theatre director in 1946 . Truman wane to comply with the subpoena on the dry land that compliance would violate the philosophy of the separation of powers .

“ The President … would become a simple arm of the Legislative Branch … if he would feel during his term of agency that his every act might be subject to official research and possible torture for political purposes ” even after he left power , Trumanwrote , and the House never held him in despite of Congress for his failure to come along . In lieu of a congressional sense of hearing , Truman denied the accusation during anational broadcastin which he detail what he knew about the allegations against White , when he knew it , and why he believed the attorney general ’s call was McCarthyist “ political skulduggery . ”

Abraham Lincoln in 1860

9. Gerald Ford

Gerald Ford’smost notable congressional testimony was on October 17 , 1974 , when he voluntarily explain to the House Judiciary Committee ’s subcommittee on criminal justice why he ’d pardonedRichard Nixon . In Ford’sopening financial statement , he said he ’d wanted “ to lurch our attentions from the pursuit of a fallen Chief Executive to the pursuit of the urgent needs of a originate nation”—needs that would be neglected if the land “ were to remain sharply divided over whether to indict , bring to trial , and punish a former President . ” But Ford was confident that the pardon “ will not cause us to draw a blank the evil of Watergate - type offense or to draw a blank the lessons we have learned that a government which deceives its champion and treats its opponent as enemies must never , never be digest . ”

Fordappearedbefore congressional citizens committee twice after he left agency in 1977 : once in 1978 to defend the 1963–1964 Warren Commission ’s conclusions on theJFK assassination(Ford had served on the commission ) , and again in 1983 tooffer adviceon how to lionize the 1987 bicentennial day of remembrance of the Constitution .

Theodore Roosevelt in 1910

William Howard Taft in 1908

Woodrow Wilson at the Paris Peace Conference in 1919

President Truman and Former President Hoover Shaking Hands in 1945

Harry Truman in november 1953

Gerald Ford testifies during House Judiciary Committee hearing on October 17, 1974