Sarah Garnet was a pioneering principal in the New York City public school system and one of the most important early suffragists. As an educator she helped to integrate New York City schools, and as a suffragist she helped to organize the Equal Suffrage Club, which worked for women's rights beyond Garnet's own lifetime.
Sarah was born in Queens County, New York, in an area now in Brooklyn, in 1831, the eldest of ten children. She was named Minsarah J. Smith, but her first name was commonly shortened to the familiar Sarah. Her parents, Sylvanus, a prosperous pig farmer, and Ann Eliza Smith, were of mixed Native American, White, and African-American descent. However, in 1845, at the age or fourteen, she began teaching at a black school in Williamsburg, later a part of Brooklyn. At an early age she married Samuel Tompkins they had two children, both whom died at an early age. .
Sarah's teaching experience and additional training after her first job at the age of fourteen are unknown. However, by 1863 she had advanced far enough in her profession to earn an appointment as principal of two black schools in Manhattan: Grammar School Number four, which became Public School Number Eighty-one and public School Number Eighty. She was the fist black woman to be a principal in the New York City public school system, and she held both positions till she retired in 1900.
During her first twenty years as principal, New York City maintained separate schools for blacks and whites. In 1883 the Board of Education proposed closing three of the black schools, but Sarah, among others, testified against the proposal before the state legislature. In 1884, to resolve the issue, the legislature passed a law allowing students of any race to attend either the previously all-white or the previously all-black schools. Separate staffs, however, remained in place at all schools. Sarah, then, had only black students from 1863 to 1883, after which she had integrated student bodies, while her staffs were all black throughout her tenure.