Yuma County was created in 1864, following the organization of the Arizona Territory in 1862, and was one of the four original counties along with Yavapai, Mohave, and Pima. With the arrival of E.F. Sanguinetti and John Gandolfo in the late 19th century, a business empire was born and a community developed. Due to the creation of stores, farms, and the mining industry, the area's population grew from 4,415 in 1900 to 224,427 in 2015. Now a ghost town, the original county seat was formed in La Paz. By 1871, it was relocated 100 miles south to Arizona City, which was renamed Yuma in 1873. In 1982, Yuma County was divided in half, creating Yuma and La Paz Counties.