Henry Frederick MacGregor, Houston businessman and Republican politician, son of Lewis Akin and Augusta Watts (Blodgett) MacGregor, was born on April 25, 1855, at Londonderry, New Hampshire, and was educated at Pinkerton Academy in Derry, New Hampshire. He graduated from Bryant and Stratton Commercial College, Manchester, New Hampshire, in 1871. Two years later he moved to Houston, Texas, and for the next fifty years he was associated with a variety of Texas commercial ventures. MacGregor was married on December 10, 1885, to Elizabeth Stevens of Houston; they had no children. He was secretary of the Galveston Railroad Company from 1879 to 1883; he was vice president and general manager of the Houston Railroad System from 1883 to 1903; after 1903 he was involved with real estate and other investments as well as the State Land-Oil Company, the Houston Post (with Governor William P. Hobby), the Bay and Bayou Company, the South Texas Commercial National Bank, the Houston Printing Company, and the Glen Park Company.
MacGregor joined with the Black and Tan faction of the Republican party during the 1880s and remained a leader in the party until his death. From 1894 to 1896 he was chairman of the Republican State Executive Committee, and in 1904 he was an unsuccessful candidate for Congress in the district around Houston. When the GOP split in 1912 between the supporters of Theodore Roosevelt and William Howard Taft, MacGregor headed Taft's reelection campaign among Texas Republicans. He was named Republican national committeeman at the party's 1912 national convention in Chicago, after Roosevelt and his followers withdrew to form the Progressive or Bull Moose party. As national committeeman, MacGregor directed Texas Republican affairs from his Houston business offices for the next eleven years. Although he was forced to fight off challenges to his leadership of the state party by Rentfro B. Creager, who became national committeeman after 1923, MacGregor was renamed to the post in 1916 and 1920. As national committeeman he was also referee of federal patronage in Texas during the remainder of Taft's presidency and for a short period under Warren G. Harding. But when the Democrats gained power under Woodrow Wilson in 1913, MacGregor presided over a weakened state GOP. When he supported Illinois governor Frank Lowden for the 1920 Republican nomination, he alienated Harding, who placed his confidence in other Texas leaders upon assuming the presidency, though MacGregor technically kept his post as national committeeman. He died on September 3, 1923, at his summer residence in Londonderry, New Hampshire, and is buried in Glenwood Cemetery, Houston.