Final answer:
President Nixon resigned during the impeachment process on August 8, 1974, before the full House could vote. The release of the tapes revealing his knowledge of the Watergate break-in contributed to his decision.
Step-by-step explanation:
President Nixon resigned during the impeachment process on August 8, 1974. Before the full House could vote on his impeachment, the U.S. Supreme Court ordered Nixon to release the actual tapes of his conversations related to the Watergate scandal. These tapes revealed that Nixon had been told about White House involvement in the Watergate break-in. Faced with the prospect of being found guilty by the Senate and removed from office, Nixon chose to resign instead.