Stimson was born on August 24, 1844 in Paterson, New Jersey.
His parents were Henry Clark Stimson (1813–1894) and Julia Maria (née Atterbury) Stimson (1819–1908).
His siblings included Henry A. Stimson (1843–1936),  Catherine Boudinot Stimson Weston (1846–1942), Mary Atterbury Stimson (1848–1928), John Ward Stimson (1850–1930), William Frank Stimson (1853–1872), Frederick Julian Stimson (1856–1926), and Julia Josephine Stimson (1861–1933), who was married to Dr. Henry Patterson Loomis.
 He was the uncle of Alfred Lee Loomis (1887–1975), the inventor of the LORAN Long Range Navigation System.

Stimson attended and graduated from Yale University in 1863, followed by medical school at Bellevue Medical College.
Stimson was born on August 24, 1844 in Paterson, New Jersey. His parents were Henry Clark Stimson (1813–1894) and Julia Maria (née Atterbury) Stimson (1819–1908). His siblings included Henry A. Stimson (1843–1936),  Catherine Boudinot Stimson Weston (1846–1942), Mary Atterbury Stimson (1848–1928), John Ward Stimson (1850–1930), William Frank Stimson (1853–1872), Frederick Julian Stimson (1856–1926), and Julia Josephine Stimson (1861–1933), who was married to Dr. Henry Patterson Loomis.  He was the uncle of Alfred Lee Loomis (1887–1975), the inventor of the LORAN Long Range Navigation System.
Stimson attended and graduated from Yale University in 1863, followed by medical school at Bellevue Medical College.
Lewis Atterbury Stimson