Elisha King Root for Samuel Colt, Experimental Pocket Pistol, Serial number 5, caliber .265 inches, barrel length 3 inches, overall length 7 inches, brass, steel, and iron, 1849-50 (Wadsworth Atheneum Museum of Art, Hartford, Bequest of Elizabeth Hart Jarvis Colt)
Additional resources:
This object at the Wadsworth Atheneum Museum of Art
Colt biography from Connecticut History
Museum of Connecticut History Research Guide for Colt Manufacturing