From Wikipedia
Episode Twelve
Surrender
On January 15, 1973, citing progress in peace negotiations, Nixon
announced the suspension of all offensive actions against North
Vietnam, to be followed by a unilateral withdrawal of all U.S. troops.
The Paris Peace Accords
on "Ending the War and Restoring Peace in Vietnam" were signed on
January 27, officially ending direct U.S. involvement in the Vietnam
War.