He was born in Poughkeepsie, New York. He completed preparatory studies and graduated from Rutgers College, New Brunswick, New Jersey, in 1843. Van Wyck studied law, and was admitted to the bar in 1847 and commenced the practice of law. He then moved to Bloomingburg, New York, where he was a district attorney 1850-1856.

Van Wyck was elected to the U.S. House of Representatives as a Republican from New York to the Thirty-sixth and Thirty-seventh Congresses (March 4, 1859-March 3, 1863). He served as chairman, Committee on Mileage (Thirty-sixth Congress) and on the Committee on Revolutionary Pensions (Thirty-seventh Congress). He entered the Union Army as colonel of the Fifty-sixth Regiment, New York Volunteers, and commanded it during the Civil War; he was brevetted brigadier general for services during the war. elected to the Fortieth Congress (March 4, 1867-March 3, 1869); successfully contested the election of George W. Greene to the Forty-first Congress and served from February 17, 1870, to March 3, 1871.

He moved to Nebraska in 1874, where he settled on a farm in Otoe County, and engaged in agricultural pursuits. Van Wyck was a delegate to the State constitutional convention in 1875. He was elected to the State senate 1877, 1879, 1881. That year, he was elected as a Republican to the United States Senate from Nebraska and served from March 4, 1881, to March 3, 1887. He served as chairman, Committee on the Mississippi River and Its Tributaries (Forty-seventh Congress) and on the Committee on the Improvement of the Mississippi River and Tributaries (Forty-eighth and Forty-ninth Congresses). Van Wyck was an unsuccessful candidate for reelection. In 1892, he was an unsuccessful Populist candidate for Governor of Nebraska. Van Wyck then retired from political life and active business pursuits. He died in Washington, D.C., October 24, 1895, and was interred in Milford Cemetery, Milford, Pennsylvania.