For more than ten thousand years the Beaver Valley and surrounding prairie, with their abundant water and wildlife, nurtured Native Americans. The Pawnee Indians, whose permanent earthlodge villages were a few miles to the south, claimed this area for hunting, fishing, and trapping.
On August 14, 1871, A. T. Coquillard, president of the St. Edward Land and Immigration Company of South Bend, Indiana, purchased 320 acres from the Union Pacific Railroad. A townsite called "Beaver City" was surveyed, but remained mostly undeveloped as settlement slowed during the grasshopper plagues of the mid-1870s. Beaver post office was established in 1872 at the sod house of Capt. Robert Hardy, one of the first settlers. In 1874 the post office was moved to the west side of Beaver Creek and the settlement was renamed Waterville.
The building of a grist mill in 1876-77 attracted settlers and businesses. The present townsite was platted and named St. Edward in honor of Rev. Edward Sorin, founder of Notre Dame University. St. Edward was incorporated October 6, 1884. It is the only town so named in the United States.