Ralph Heyward Isham (born July 2, 1890, New York City—died June 13, 1955, New York City) was an American collector of rare manuscripts who discovered the long-missing manuscripts of James Boswell’s Life of Samuel Johnson and other Boswell papers and letters.
The son of a wealthy railroad executive, Isham attended Cornell University (1908–09) and Yale University (1910–11), went big-game hunting in Mexico and the Malay Peninsula, and then wrote a series of newspaper articles. In London from 1916 to 1919 he served in the British Army, rising in the ranks to become a colonel (with the permanent rank of lieutenant colonel) and acquiring a somewhat British accent and manner. In civilian life thereafter he continued to affect the name of “Colonel Isham.”
Although, back in New York City, he held some corporate offices at times, he became principally a book and manuscript collector, traveling frequently abroad. In 1927 he sought out some Boswell papers from Boswell’s great-great-grandson, the 6th Baron Talbot de Malahide, at Malahide Castle, near Dublin. For more than 20 years Isham continued the reassembly of Boswell’s papers, finding most of the papers at Malahide Castle or at Fettercairn House, Scotland; the manuscripts were uncovered in old boxes and bundles in attics and other half-hidden reaches. In 1948 Isham announced the completion of the collection (though a few more pieces were still to be discovered at Malahide, Fettercairn, and other sites after Isham’s death).
Isham himself privately published The Private Papers of James Boswell, from Malahide Castle, in the Collection of Lt.-Colonel Ralph Heyward Isham (1928–34) and secured the commercial publication of Boswell’s Journal of a Tour to the Hebrides (1936). In 1949 he sold the bulk of the collection to Yale University for $450,000, a great sum at the time; he sold his remaining Boswellian items to Yale in 1950. In January 1950 Professor Frederick A. Pottle of Yale began the massive task of sorting and cataloging the Boswell papers; the first volume, London Journal, 1762–1763, was published in November.