The Tenure of Office Act, passed over the veto of President Andrew Johnson on March 2, 1867, provided that all federal officials whose appointment required Senate confirmation could not be removed without the consent of the Senate. When the Senate was not in session, the Act allowed the President to suspend an official, but if the Senate upon its reconvening refused to concur in the removal, the official must be reinstated in his position. It was not entirely clear whether the Act applied to cabinet officials appointed by a previous president, such as Secretary of War Edwin Stanton, a Lincoln appointee.
In the summer of 1867, with Congress not in session, Andrew Johnson decided the time had finally come to replace Edwin Stanton with a new secretary of war. Stanton had become increasingly at odds with Johnson and the rest of his cabinet, and had been conspiring with Radical Republicans in Congress to thwart Johnson's policies on Reconstruction, which were considered too soft by the Radicals. On August 5, 1867, Johnson sent Stanton the following message: "Public considerations of high character constrain me to say that your resignation as Secretary of War will be accepted." Stanton refused to resign, forcing Johnson to send Stanton a second letter suspending him from office, ordering that he cease all exercise of authority, and transferring power to a new secretary of war, Ulysses S. Grant.
On January 3, 1868, the new Congress met and refused to concur in the removal of Stanton by a vote of 35 to 16. The President, however, refused to accept the Senate's decision, believing the Tenure of Office Act to be an unconstitutional infringement on the power of the executive. Hoping to obtain judicial review of the Act's constitutionality, Johnson on February 21, 1868 appointed General Lorenzo Thomas, Adjutant General of the Army, to the post of secretary of war. Stanton balked at leaving the office he had reoccupied since January. Charles Sumner, one of the Senate's leading Radical Republicans, sent Stanton a one word telegram: "Stick." Impeachment proceedings began within days.
Although both Presidents Ulysses Grant and James Garfield complained strenuously about the Tenure of Office Act, the Act was not repealed until 1887, at the urging of then President Grover Cleveland.
In 1926, in the case of Myers vs. United States, the Supreme Court, in an opinion by Chief Justice Taft, held unconstitutional a law requiring the consent of the Senate for removal of certain non-Cabinet officials.