United States Coast Survey. "A diagram of the triangulation for the survey of the coast of the United States, made in 1817 and 1833, and the secondary triangles made in 1833 & 1834 in Connecticut & upon Long Island." Map. Washington: United States Coast Survey, [1830?–1839?]. Norman B. Leventhal Map & Education Center, https://collections.leventhalmap.org/search/commonwealth:7h14b209j (accessed May 14, 2024).