William Frelinghuysen was an American politician and member of the Republican Party. He served as a U.S. Congressman from New Jersey from 1903 to 1911. Frelinghuysen was known for his involvement in various legislative efforts during his time in office, focusing on issues such as agriculture and public works. Born on December 24, 1859, Frelinghuysen came from a prominent family with a history in politics. He was the grandson of Frederick Frelinghuysen, a notable U.S. Senator. After his congressional career, he continued to be active in public service and community affairs until his passing in 1936.