Caleb Goldsmith Forshey was born on July 18, 1812, in Somerset County, Pennsylvania.

He was an engineer, scientist, and educator. He attended Kenyon College in Ohio (1831-1833) and the United States Military Academy at West Point (1833-1836) but apparently did not graduate. He was a professor of mathematics and civil engineering at Jefferson College in Washington, Mississippi (1836-1838). Forshey was then employed in engineering projects along the Mississippi River. In 1848, at Carrollton, Louisiana, he constructed a hydrologic station that measured the flow of the river from 1848 to 1855 for the federal government's Mississippi Delta Survey. In 1853, he moved to Texas to become chief engineer of the newly chartered Galveston, Houston and Henderson Railroad. He published scientific articles in many of the leading journals of the 1840s and 1850s. He also contributed articles on the meteorology and climate of Texas to the Texas Almanac in 1860 and 1861. In 1854, he founded the Texas Military Institute in Galveston and conducted it till 1861 when he entered the Confederate service as a lieutenant-colonel of engineers. As a chief engineer on the staff of Gen. Magruder, he planned the defences of the Texas frontier and the operations of a recapture of Galveston and the Texas coast. In 1866, he published a report proposing a system of railroads designed to lead from the port of Galveston into the interior of Texas. He was the first vice-president and one of the founders of the New Orleans Academy of Sciences. He assisted in the preparation of "The Physics of the Mississippi River" (1861).

In 1836, he married Margaret Monroe. In 1843, he remarried Martha Annie Williams (1818–1850) and in 1853, he remarried Mary Eunice Williams (1830–1894). He died on July 25, 1881, in Carrollton, Louisiana.