[2][3] She was born in Seneca Falls, New York, the daughter of Eunice Newton, a scientist and women's rights campaigner, and Elisha Foote, a prominent lawyer and judge, and the niece of Senator Samuel A.

[4] In June 1868, she married John B. Henderson, Senator from Missouri (1862–1869) who introduced the thirteenth amendment to the Constitution that abolished slavery and one of seven Republicans who voted against the impeachment of President Andrew Johnson in May 1868.

[5] That unpopular decision ended his career as senator, and he and his new wife moved back to Missouri, living first in the town of Louisiana and then in St.

Purchased at ten cents on the dollar, the bonds became valuable when the courts ordered counties to pay Henderson their full face value.

Mary Henderson's interest in the immediate neighborhood, which coincided with the City Beautiful Movement of the early 20th century, ultimately led to the construction of the Meridian Hill Malcolm X Park[7] and eviction of the community of working-class African Americans who resided in the area.

[9] She supported two successive plans, by architect Paul J. Pelz in 1898 by Franklin W. Smith in 1900, to construct a colossal presidential mansion on Meridian Hill to replace the White House.

While she actually succeeded in having legislation passed to change the name of the street in 1913, the Commission of Fine Arts denied her request to construct the busts.

A report by the Commission stated:[6] Persistently she labored during four decades, persuading and convincing Senators and Representatives; single-handed and alone she appeared before committees of Congress to urge approval for the work of development.