Complex sentence: Peters was elected as a Republican to the Fortieth, Forty-first, and Forty-second Congresses (March 4,1867-March 3,1873), but declined to be a candidate for renomination in 1872.
Split into simpler sentences: Peters was elected as a Republican to the Fortieth, Forty-first, and Forty-second Congresses (March 4,1867-March 3,1873). He declined to be a candidate for renomination in 1872.