R. Brent Keyser, William Keyser's oldest son, was born on August 5, 1859. He attended St. Paul's School in Concord, New Hampshire from 1875-1878. After leaving St. Paul's he embarked on a European tour (June-October 1879). At his return, he began his long career in business, working in the firms connected with his father: Baltimore Copper Smelting and Rolling, Keyser Brothers, Baltimore Electric Refining Company, and the Baltimore and Ohio Railroad.
On June 14, 1888, Brent married Ellen Carr McHenry, a descendant of Col. James McHenry. They had three children: Juliana Brent Keyser, later Mrs. Gaylord Lee Clark, Ellen Keyser, who married the diplomat, James Bruce, and William McHenry Keyser.
Throughout his life, R. Brent Keyser was active in many local Baltimore organizations. He served on the boards of the B&O, Municipal Art Society, Mercantile Bank and Trust, National Union Bank, McDonogh School, Baltimore Board of Trade, the Enoch Pratt Free Library, and Hospital Relief Association. He was also Chairman of the Board of Trustees of the Johns Hopkins University from 1904-1927.
R. Brent Keyser, like his father, devoted much time and energy to promoting Hopkins. He participated in the planning and development of, and the fundraising for, the campus at Homewood.
R. Brent Keyser died on March 1, 1927. He was survived by his wife and their two daughters.