No, Nixon was not impeached. The House Judiciary Committee issued articles of impeachment, 3 articles IIRC, but the House did not vote on them. Nixon resigned like 9 or 12 days later, well before a vote could have commenced. The Senate only votes on whether to uphold the impeachment voted on by the the full House.
I lived, ate, and breathed those hearings on AFRTS back in the day. LOL
“The Senate only votes on whether to uphold the impeachment voted on by the the full House.”
The House votes articles of Impeachment, similiar to a local DA filing a criminal complaint.
THe Senate, overseen by the Chief Justice of the Supreme Court, actually tries the offender to determine guilt, and subsequentially votes whether or not to remove the offender.