Ceramicist, Antiquarian. Born the son of Mary Rebecca Chapman and William Robert Mercer, a Naval officer, in Doylestown, Pennsylvania. He was graduated from Harvard in 1879, and from the University of Pennsylvania Law in 1881, but never practiced law. After graduating he traveled in Europe and Egypt, and began a lifetime of collecting and a passion for anthropology. Upon his return to the US, he began the serious collection of American Colonial kitchen utensils, farming implements, and other superseded tools. He eventually gathered almost 30,000 items ranging from hand tools to horse-drawn vehicles and created a 13-part taxonomy for them. He was one of the founding members of The Bucks County Historical Society. In 1894, he was appointed curator of American and prehistoric archaeology at the University of Pennsylvania Museum, holding the post for three years. In 1898, he took his collecting one step further and built the Moravian Pottery and Tile Works for making Moravian-style tiles in order to revive a dying craft. All its handmade tiles were his original designs or based on historical models he had adapted. The Works earned major commissions, including the rotunda of the Pennsylvania State Capitol, which utilized almost 400 mosaics comprised of sixteen thousand square feet of tile. His tiles were purchased world wide, and won a grand prize at the 1904 World's Fair. The Pottery still produces tiles while serving as a living-history museum today. In 1914, he published 'The Bible in Iron,' a reference for cast-iron stoves of Pennsylvania German make, it is still in print. His custom, concrete mansion, Fonthill Castle, was completed in 1912. He used his home to showcase the tiles produced at the Works, and his collection of prints; over 1,000 were hung on the walls. The house is now run as a museum. In 1916, he built a 6-story concrete museum, the central atrium was used to hang objects such as a whale boat, stage coach, and Conestoga wagon. He donated the building and his collection to the Bucks County Historical Society. The Mercer Museum today houses over 40,000 artifacts. He published 'Ancient Carpenters' Tools' in 1929, and it is still in print. He succumbed to Bright's disease and myocarditis the following year. His Fonthill Castle, the Mercer Museum, and Moravian Pottery and Tile Works, make up what is now called the Mercer Mile, and are all open to the public.