congressional (adj.)

"of or pertaining to a congress," 1690s, from Latin congressionem (from congressus, see congress) + -al (1); specifically "of or pertaining to the Congress of the American states" from 1776. As such the word was at first reviled as barbarous, but Pickering (1816) quotes an unnamed English correspondent: "The term Congress belonging to America, the Americans may employ its derivatives, without waiting for the assent of the English."