[There are indications of some intrigue surrounding his residence there. An area for more research.] Read comments of a friend who visited Conway and spoke to "an eminent physician in Washington" about his condition in The Kansas Memorial: A Report of the Old Settlers Meeting Held at Bismark Grove, Kansas, September 15 and 16, 1879.(See page 129 - Letter from Martin F Conway and preceding paragraph.) Edited by Charles S. Gleed. Available at the New York Public Library (off-site. The Kansas Memorial.
See mention of Martin F Conway in personal letter of John Swinton, managing editor of the New York Times, to Walt Whitman, 25 February 1863, at WALT WHITMAN ARCHIVES
