Stalwart, in U.S. history, member of a faction of the Republican Party that opposed the civil-service reform policies of President Rutherford B. Hayes and sought unsuccessfully a third presidential term for Ulysses S. Grant. The Stalwarts, or regular Republicans, vied with the generally more liberal Half-Breeds for control of the party in the 1870s and ’80s. Among Stalwart leaders were Roscoe Conkling of New York and Chester A. Arthur, vice president under James A. Garfield.