Windsor's first European settlers arrived in 1851. In 1855, Hiram Lewis, a Pony Express rider, became the town's first postmaster. He named the town Windsor because it reminded him of the grounds around Windsor Castle, a medieval castle from his home country of England. In 1855, a post office was established in Windsor. The following year, a business enterprise was built in eastern Windsor, which included a goods store, a shoe shop, a grocery and meat market, a saloon, a hotel, a boarding house, and two confectionery shops. The Northwestern Pacific Railroad was completed through the town in 1872, providing a faster and cheaper link to the Bay Area.