Friedrich agrees deal with Chicago Fire
The defender, who won 82 caps for Germany and played in the 2006 and 2010 World Cups as well as Euro 2008, said he chose the offer from the United States over several others from the Bundesliga and other European clubs.
"I am happy to announce that I will from this moment tie my shoes for Chicago Fire," he said on his website on Thursday.
"I am proud to be able to realise my ambitions at a club like Chicago Fire."
Friedrich, 32, had joined VfL Wolfsburg in 2010 but underwent back surgery and has not played since dissolving his contract voluntarily last September.