I think Richard Nixon is the most corrupt US president ever. Richard Milhous Nixon was the 37th President of the United States, he is the only president to resign the office as a mean to avoid being impeached over the Watergate scandal. Watergate isn't the only scandal that tarred Nixon and his administration.
Vice President Agnew resigned a year before for reasons not related to Watergate: he was convicted on charges of bribery, tax evasion and money laundering during his tenure as governor of Maryland.
Nixon's CIA director, was convicted of conducting illegal surveillance on U.S. journalists and plotting assassinations in Chile.
Nixon's secretary had to resign after less than three months in office after altering a negative finding (while transcribing the tape) against a Nixon.
The most corrupt United States president was, still is, and will probably always be, Donald Trump. He has lied and lied about so many things and I believe he lies to cover up his corruption. He thinks he is such a great negotiator but he’s actually an awful negotiator. What did he do with all the money he collected for veterans at the rally he held instead of attending one of the presidential debates during the campaign?
What has he done with all the money his inaugural committee raised? What has he done with all the money his Trump Tower has made from visitors? He was supposed to donate it. Instead he costs the United States taxpayers millions of dollars with all his trips to Mara Lago so he can play golf when he should be working.