In 1908, Oldfield won election to the
61st Congress. He was reelected ten times and served from March 4, 1909, until his death. Oldfield was chairman of the
Committee on Patents in the
62nd and
63rd Congresses, and Minority
Whip from the
67th through
70th Congress. In addition, he served on the
Ways and Means Committee and served as chairman of the
Democratic Congressional Campaign Committee. Oldfield won reelection to the
71st Congress in 1928, but died before the term started in March 1929. He was succeeded in Congress by his wife
Pearl P. Oldfield. ==Death and burial==