Collection consists of correspondence, diaries, account books, deeds, abstracts of titles, certificates, tax records, clippings, and other material related to George Washington Kassler. Born in Canajoharie, New York in 1836, Kassler settled in Omaha City in Nebraska Territory in 1857, working as a clerk. In 1860 he traveled west to the fledgling Territory of Colorado, becoming a cashier at a local bank. In 1862 he was appointed assistant cashier of the United States Banch Mint at Denver, but by 1863 he had joined with David H. Moffatt and others to open a new wholesale and retail store in Denver. By 1880 he became a cashier at Moffat's First National Bank of Denver. Throughout his career as a businessman, Kassler invested in a number of mining and railroad ventures, and by the time of his death in 1890 he had become one of Denver's most prominent citizens.