Born in Philadelphia. Brother of Henry Chapman. Educated at Friends School. Married to Bertha Jayne Bucknell. They had three sons.
He began to collect stamps in 1867. In 1876 he learned the coin business as an employee of John W. Haseltine of Philadelphia. In June 1878 he joined his brother in the business. His personal library was described as the finest numismatic library in existence. He held the office of ANA librarian at a time when the collection consisted of copies of the The Numismatist and Plain Talk. A later inventory showed that they had acquired their first book. He was a charter member of the ANA and member number 28. He was also a member of the ANS. His area of special interest was Greek and Roman coins.
He conducted 28 auction sales from 1907 to 1924 after seperating from his brother. He retired as a dealer about 1929. He died in Philadelphia. Chapman remainders were sold at auction by Thomas Elder in 1932.
Author of United States Cents of the Year 1794 in 1923. About 100 copies were printed. Criticism by George Clapp caused Chapman to withhold distribution in favor of a 1926 revision.
In 2010 he was inducted into the PCGS CoinFacts Coin Dealer Hall of Fame.
bio: NUM 4 Feb 1892 suppliment (photo) obit: NUM 44 Nov 1931 pages 793-794 (photo); ANAHist 465