Eddie O'Sullivan ended his ties to the United States for a second time when he decided not to reapply for the coaching job on Wednesday.
After resigning as Ireland coach in 2008, O'Sullivan took over the Eagles in 2009 and qualified them for the recent World Cup in New Zealand.
There they beat Russia for their first World Cup win in eight years. They were also competitive against Ireland and Italy but lost heavily to eventual third-placed Australia.
"The Eagles' performance at the Rugby World Cup speaks volumes about him and the way he prepared the team," USA Rugby CEO Nigel Melville said.
O'Sullivan was the Eagles assistant coach at the 1999 World Cup then led Ireland at the next two tournaments.