The United States has had diplomatic relations with the nation of Germany and its principal predecessor nation, the Kingdom of Prussia, since 1835. These relations were broken twice (1917 to 1921, and 1941 to 1955) while Germany and the United States were at war and for a continuation interval afterwards. Prior to 1835, the United States and Prussia recognized one another but did not exchange representatives, except for a brief period when John Quincy Adams was accredited to the Prussian court from 1797 to 1801.