The Utah Territorial Legislature approved a plan to locate the capital in the Pahvant Valley.

On October 28, 1851, Utah governor Brigham Young chose the specific site for Fillmore.

Anson Call headed the colonizing company that shortly followed; they built houses, a grist mill, and a sawmill.

Captain John W. Gunnison, leading a military party surveying the region, was attacked by a band of Pahvants (Ute) west of Fillmore.

However, in 1856, the legislature decided to move the Territorial Capital to the larger community of Salt Lake City.

According to the United States Census Bureau, the city has a total area of 5.8 square miles (14.9 km2), all land.

In 1853, 304 people were recorded as belonging in the LDS Church congregation when John A. Ray replaced Anson Call as the leader of the Mormons in Fillmore.

[6] As of the 2000 United States Census, there were 2,253 people, 732 households, and 562 families in the city.

21.9% of all households were made up of individuals, and 12.4% had someone living alone who was 65 years of age or older.

The ethnic and racial make-up of the population was 78.7% non-Hispanic white, 1.1% Native American, 1.6% Asian, 0.1% Native Hawaiian, 2.3% reporting two or more races, and 17.2% Hispanic or Latino.