John Cobleigh had four sons: Luke, George, John R. and Lyman, and one daughter, Lucy. Luke Cobleigh married Charlotte Monroe, and their daughter, Kathrina Augusta, was born on September 18, 1868 in Gardner, Massachusetts. Kathrina graduated from Mount Holyoke in 1892 and taught high school until her marriage on September 9, 1896 to George W. Quick. George Quick graduated from Richmond College, and Crozier Theological Seminary. Together, they had two children, Virginia Monroe, and Richard Biggs, both born in Springfield, Massachusetts. Virginia Monroe Quick graduated from Mount Holyoke College in 1922, and went on to teach Latin at many high schools. On March 8, 1936, Kathrina Cobleigh Quick died in Chevy Chase, Maryland. Virginia Monroe Quick died on April 8, 1985 in Washington, D.C.

Chiefly letters by or to John Cobleigh, his sons, Luke, George, John R., and Lyman, all of Princeton and Winchendon, Mass., and his daughter, Lucy Ann Foristall, of Fitzwilliam, N.H., 1847-1859, discussing family news, local events, and the brothers' employment as wood workers in sawmills. Includes letters describing the California gold mining experience of Luke and John, 1852-1854, and George's work on railroad construction in Chicago, 1855-1857. Also includes Luke's diary, 1860, and account books, 1861-1865.