Mary Arthur McElroy presided at the White House when her brother, Chester Alan Arthur succeeded to the Executive office upon the death of President Garfield. In 1859 he had married Ellen Lewis Herndon, daughter of Commander William Lewis Herndon, who, by order of the Government, explored the Amazon River in 1857, but she died in January, 1880, less than one year previous to his election as Vice-President. Mrs. McElroy was specially adapted to fill such a position from her natural tact and previous social experience. Her residence at the White House was therefore marked by graceful and dignified hospitality and the task of entertainment was greatly lightened by the extreme geniality of the President. Like her brother, she was of fine and imposing appearance. After the death of Mr. Arthur his only daughter Ellen Herndon Arthur, lived in Albany with her aunt, Mrs. McElroy, the son, Chester A. Arthur Jr., residing chiefly abroad.