Mary Arthur McElroy

Mary McElroy (; July 5, 1841 – January 8, 1917) was an American woman known as being the sister of the 21st president of the United States, Chester A. Arthur, for whom she served as a hostess (acting as the first lady) for his administration (1881–1885). She assumed the role because Arthur's wife, Ellen, had died nearly two years earlier.

McElroy was born in New York and attended the progressive Emma Willard School. She married insurance salesman John Edward McElroy and worked for some time as a teacher. When her brother Chester A. Arthur became president, she lived in the White House during winter months to host social events and care for her niece. As acting first lady, McElroy ended the tradition of suspending social events during Lent, and she held large weekly receptions. She was a popular hostess, and contemporary Washington social life celebrated her for her lively receptions.

When her tenure as hostess ended, McElroy returned to her family in Albany, New York, and she later worked in Ireland to preserve the Arthur family homestead. She handled her brother's affairs during his illness and after his death, taking responsibility for his funeral and his presidential legacy. McElroy died in Albany in 1917. She is one of the most obscure first ladies, and relatively little scholarly research about her life exists.

Early life Mary Arthur was born in Greenwich, New York, the last of nine children born to William and Malvina S. Arthur. Arthur's mother, Malvina Stone, was born in Vermont, the daughter of George Washington Stone and Judith Stevens. Malvina's family was primarily of English and Welsh descent, and her grandfather, Uriah Stone, fought in the Continental Army during the American Revolution. Her father, William Arthur, was born in Dreen, Cullybackey, County Antrim, Ireland; he graduated from college in Belfast and emigrated to Canada in 1819 or 1820. Her mother met her father while William Arthur was teaching at a school in Dunham, Quebec, just over the border from her native Vermont.

McElroy attended the Emma Willard School Seminary in Troy, New York, intending to become a teacher. This school offered an education equivalent to that found in men's schools; she was educated in history, geography, science, and French. At one point, McElroy taught at a private school in Edgecombe County, North Carolina. Little else is known about her career before her work in the White House. John McElroy was a reverend and an insurance salesman who was the president of the Albany Insurance Company. They lived in Albany, New York, and had four children: May (1862–?), William (1864–1892), Jessie (1867–1934), and Charles (1873–1947). She also assisted in raising the children of her brother Chester A. Arthur when his wife Nell Arthur died in 1880. She was close to Arthur's daughter Nellie, encouraging her to pursue music in honor of her mother. McElroy quickly learned the responsibilities of White House hostess, and she described herself when starting as "absolutely unfamiliar with the customs and formalities".

McElroy began her role as acting first lady on January 24 when she participated in a diplomatic corps dinner. McElroy first hosted a reception of her own on January 27 and would host further receptions on Saturdays thereafter. Despite this, she proved to be a popular and competent hostess. Future First Ladies used the social function procedures she and her brother developed for decades. Her responsibilities typically involved hosting more formal events, as Arthur would host informal dinners himself if families were not attending. McElroy was noted for her hospitality while hosting, using a more personal style with guests.

Legacy McElroy has not been the focus of significant historical research. This is partly because of her limited time as a White House hostess and partly because of the relatively little scholarly focus on her brother's presidency.