In 1876 an investigation revealed that Secretary of War William Belknap had accepted bribes. He had been accepting bribes from companies to trade. Most believed the money was being contributed to the Republican Party.
The House of Representatives impeached him, in which he then resigned.
Grant did not seek reelection in 1876 after the public also learned that the Secretary of the navy had taken in bribes as well from shipbuilders and the Secretary of the interior had shady deals.