[7] The railroad station and post office long favored the shorter Calvert, but the Board on Geographic Names reversed its earlier decision in 1957 and switched to the longer form.

[8][9] During the Ohio River flood of 1937, Calvert City's business district and much of the residential area were severely damaged by floodwaters.

In the 1940s, the construction of nearby Kentucky Dam by the Tennessee Valley Authority brought plentiful electric power that led many industrial plants, mostly chemical manufacturers, to locate between the city and the Tennessee River.

The city limits extend southeast as far as the western shore of Kentucky Lake on the Tennessee River.

Calvert City has 16 industrial plants that are a key source of employment for Western Kentucky.

The majority are chemical manufacturers, with some steel and metallurgical plants and industrial services firms.

The city is the northern terminus of the Julian M. Carroll Purchase Parkway, providing a link to Memphis, Tennessee.

The city has rail access through the Paducah and Louisville Railway main line and is a commercial port on the Tennessee River.