Gysbert Van Steenwyk, Sr., was born in Utrecht, Holland, on January 30, 1814. At the age of sixteen years, he served as a volunteer in the army of the Netherlands for two years. From 1838 to 1849, he was a commissioned officer in the Netherlands National Guard. A well educated man, Van Steenwyk attended the University of Utrecht, taking degrees in philosophy and philology. He also studied law but did not practice it. In the winter of 1848, he decided to come to the United States with a friend, and they sailed to this country in May 1849. After touring the Midwest in September, they visited Milwaukee and other Wisconsin towns, finally deciding to settle in Milwaukee where van Steenwyk received his first appointment as Notary Public from Governor Nelson Dewey. Soon after, he received a commission from the Hague as Consul of the Netherlands for Wisconsin, Minnesota, and Michigan. During 1852-1853, van Steenwyk served as Wisconsin Commissioner of Immigration and lived in New York. Returning to Wisconsin in 1853, Van Steenwyk moved to Newport, on the Wisconsin River, where the La Crosse and Milwaukee Railroad was expected to cross. The proposed route altered, however, and most of Newport's resident moved to Kilbourn City (later called the Wisconsin Dells) in 1858, along the new route.
Gysbert Van Steenwyk, Sr. was commissioned Brigadier-General of Wisconsin State troops in 1857, and in 1859 was elected to the State Assembly from Columbia County. The following year he was a delegate to the Republican State Convention and was elected Bank Comptroller. Upon the expiration of his term in 1862, Van Steenwyk, Sr. moved to La Crosse and opened the Batavian Bank (later renamed First Bank, now called U.S. Bank). He entered politics again in 1873, serving one term as mayor of the city of La Crosse. He was elected to the State Senate in 1879.
Van Steenwyk, Sr. was one of the executors of the former Governor Cadwallader C. Washburn's will, and vice president of the board of trustees of the La Crosse Public Library. Apart from the Batavian Bank, his business interests included the Victor Flouring Mill, La Crosse Linseed Oil Mill, La Crosse Street Railway Co, Edison and Brush Electric Light and Power Cos., La Crosse Tannery, and East Bank Improvement Co.
Gysbert Van Steenwyk married Mariette Nichols in May 1875 in Berne, Switzerland. Mariette Nichols was born Sept. 8, 1848, in Danbury, Connecticut, to David Philip and Matilda (Averill) Nichols. She was active on the Board of the Home for the Friendless (also called the Home for Friendless Women & Children, later called La Crosse Home for Children; now called Family & Children's Center). The Van Steenwyks were the parents of three children: Gysbert Jr., Ella May, and Walter Charles who died at the age of eight years. Gysbert Van Steenwyk, Sr. died Sunday, April 13, 1902. His wife, Mariette, died in La Crosse October 14, 1930.