Brackenridge was a leader in Texas suffrage organizations and helped get the Nineteenth Amendment to the United States Constitution passed.

She was the eldest daughter in a family of eight children born to John Adams Brackenridge and his wife Isabella Helena McCullough.

The family moved to Jackson County, Texas, in 1853, but she remained behind and graduated in 1855 from Anderson's Female Academy in New Albany, Indiana.

[2] Her father died during the Civil War, and she and her mother later moved into the San Antonio home of her brother George Washington Brackenridge.

In San Antonio, she was active in the Women's Christian Temperance Union (WCTU), the Order of the Eastern Star and the Presbyterian Church.

[3] In 1906, Brackenridge was named vice-president of the San Antonio Health Protection Association, formed to combat tuberculosis in the city.

The departments represented needs such as legal issues, employment for women, health needs, community activism, and educational needs.

The three influential women who served on that first board were instrumental in the establishment of the university: Mary Eleanor Brackenridge, Texas WCTU president Helen M. Stoddard and Eliza S. R. Johnson, wife of State Senator Cone Johnson and daughter of Elijah Sterling Clack Robertson.

The Mary Eleanor Brackenridge Club at TWU was established to help broaden the cultural awareness of its members.

[16] Mary Eleanor Brackenridge was a founding member and the first Regent of the San Antonio de Bexar Chapter,[1] Daughters of the American Revolution, qualified by her ancestor, Charles Baskin through her maternal lineage.

[17] The Brackenridge name in Texas descended from Scotch-Irish Robert Breckenridge Sr., who emigrated from Northern Ireland with his brother Alexander c1730.

[22] John Adams Brackenridge (1800–1862) was a graduate of Princeton University and a politically active lawyer in Warrick County, Indiana.

[23] The lineage of James McCullough's wife Mary Craig Grimes was the criteria for acceptance into the Daughters of the American Revolution.

The DAR certified that Charles Baskin (1741–1822) served during the American Revolutionary War under General Daniel Morgan.

[24] Sometime after the death of her father in 1862, Eleanor and her mother Isabella moved into her brother George's home in San Antonio.

[28] Robert John Brackenridge (1839–1918) served in the Confederate States Army in his brother Tom's unit in Texas.

[31] Lenora Helena Brackenridge Matthews (1842–1918) was a civic activist who helped establish a local chapter of the American Red Cross.

She died of a cerebral hemorrhage on February 14, 1924, and is buried in the family cemetery in Jackson County, Texas.