How many presidents returned to congress after serving as president?

One.

Only John Quincy Adams, see http://americanhistory.suite101.com/article.cfm/john_quincy_adams_dies_in_congress Unfortunally http://wiki.answers.com/Q/User:Matthewra. is wrong thiers accuatly 2 I dont know who was the toher one btu I knwo there's only 2 presidents ty-Learn.com The answer is TWO (2) John Quincy Adams and Andrew Johnson