Bellflower is in southeastern McLean County, along Illinois Route 54, which leads southwest 9 miles (14 km) to Farmer City and northeast 12 miles (19 km) to Gibson City.

According to the U.S. Census Bureau, Bellflower has a total area of 0.36 square miles (0.93 km2), all land.

Bellflower was laid out on August 26, 1871, by George Nelson Black (March 15, 1833 – April 22, 1908) and his wife Louisa J.

George was born in Berkshire County, Massachusetts, and had come to Springfield, Illinois, in 1850, where he became wealthy through manufacturing, mining, and railroads.

[4] Bellflower Township had subscribed $30,000 in twenty-year bonds toward the construction of what was then called the Gilman, Clinton and Springfield Railroad.

Most of the western square was divided into sixteen blocks, each usually containing twelve lots, and this part of the town was split diagonally by the 100-foot-wide (30 m) path of the railroad.

The small triangle of land cut off by the railroad from the remainder of block ten became the location of the town jail.

The station was located on the south side of the tracks, and the two early elevators were on railroad land.

Bellflower quickly became a major grain shipping center serving the fertile surrounding land.