Stephen Harriman Long

Stephen Harriman Long
Representation of the 1819 oil painting of Major Long. Portrait painted by Charles Willson Peale
Born(1784-12-30)December 30, 1784
DiedSeptember 4, 1864(1864-09-04) (aged 79)
EducationDartmouth College
SpouseMartha Hodgkins
Parent(s)Moses and Lucy (Harriman) Long
Engineering career
DisciplineCivil Engineer, Topographical engineer, explorer, inventor.
InstitutionsUS Army Corps of Engineers (1814-38), United States Army Corps of Topographical Engineers (1838-63).
Employer(s)Baltimore and Ohio Railroad, Western & Atlantic Railroad.
ProjectsFederal expeditions in the trans-Mississippi West (1817–1823); federal internal-improvements surveys (1824–early 1830s); early railroad route studies and engineering.
Significant designThe Long truss

Stephen Harriman Long (December 30, 1784 – September 4, 1864) was a United States Army officer, topographical engineer, civil engineer, and inventor whose career combined military engineering, scientific exploration, federal internal improvements, and early railroad and bridge development.

He is best known for leading federal exploratory expeditions in the trans-Mississippi West between 1817 and 1823, including the 1820 reconnaissance of the Great Plains that contributed to the contemporary characterization of portions of the region as the “Great Desert.”

From the mid-1820s onward, Long played a significant role in federally authorized surveys under the General Survey Act and in early railroad development, including work associated with the Baltimore and Ohio Railroad and the Western & Atlantic Railroad.

In 1830, he patented the Long truss, an early timber bridge system that incorporated adjustable compression bracing and deliberate proportioning of members according to calculated stresses, a design later identified by historians as an early application of analytical principles in American bridge engineering.