Complex sentence: Stockbridge was elected as a Republican to the Fifty-first Congress (March 4,1889-March 3,1891), but declined to be a candidate for renomination in 1890.
Split into simpler sentences: Stockbridge was elected as a Republican to the Fifty-first Congress (March 4,1889-March 3,1891). He declined to be a candidate for renomination in 1890.