[44] At that time, the state was the scene of a brutal struggle between pro-slavery and anti-slavery forces, and Arthur lined up firmly with the latter.[47] The rough frontier life did not agree with the genteel New Yorkers; after three or four months the two young lawyers returned to New York City, where Arthur comforted his fiancée after her father was lost at sea in the wreck of the SS Central America.[47] In 1859, they were married at Calvary Episcopal Church in Manhattan.[48] The couple had three children:

William Lewis Arthur (December 10, 1860 – July 7, 1863), died of "convulsions"
Chester Alan Arthur II (July 25, 1864 – July 18, 1937), married Myra Townsend, then Rowena Graves, father of Gavin Arthur
Ellen Hansbrough Herndon "Nell" Arthur Pinkerton (November 21, 1871 – September 6, 1915), married Charles Pinkerton
After his marriage, Arthur devoted his efforts to building his law practice, but also found time to engage in Republican party politics. In addition, he indulged his military interest by becoming Judge Advocate General for the Second Brigade of the New York Militia.