The International Parliamentary Scholarship of the German Parliament is accepting applications through June 30th, 2017! This unique opportunity to intern in the Bundestag alongside young professionals from over 40 other countries runs from March - July 2018.
Candidates must be American citizens with advanced German proficiency no older than 30 years of age by the time the program begins in March 2018. They must also have received a bachelor's degree by December 31st 2017, and have a demonstrated interest in social and political engagement. All majors are eligible. 

A summary of the program in English is available here:
https://www.bundestag.de/en/europe/international/exchange/ips/ips/201258 

...and a more detailed German version including links to the application documents is here:
http://www.bundestag.de/europa_internationales/internat_austausch/ips/usa/245064 

The American alumni association also maintains a public Facebook page where candidates can interact with alumni and current participant.