Merrill was born on 24 September 1862 in Ripon, Wisconsin. Nothing is known of her parents, but it can be assumed they were financially stable, as private tutors provided Merrill's early education. In 1883 she graduated with a B.A. degree from Wellesley College, Wellesley, Massachusetts.
After working at Harvard, in 1884 Merrill applied, to Columbia University, in New York, to be allowed to study mathematics and astronomy. Up until this time Columbia University was an institute for men only and due to this was the case Merrill's initial request was refused. However, with the support and advice of Frederick A P Barnard, the 10th president of Columbia University who was a campaigner for women's education, Merrill visited each trustee individually to plead her case. She argued the points that to be able to study astronomy Merrill needed a telescope and only Columbia University had one and also that the Professor of Astronomy required an assistant at the time. At the next meeting of the trustees, they voted to allow Merrill to pursue her studies individually. Her work in the field of mathematical astronomy included in 1883 the computation of the orbit of a comet. On completion of the required credits, and having written an original thesis that:-
...dealt with geometric interpretations of multiple integrals and translations and relations of various systems of co-ordinates,Merrill applied to the trustees to be awarded a Ph.D. In 1886 Merrill became the first American woman to be awarded such a distinction in mathematics, which she earned cum laude.
She was offered a position as a professor of mathematics at Smith College in 1887, which she declined, as that year Merrill married Frederick James Hamilton Merrill, an 1885 graduate of Columbia's School of Mines who received his Ph.D. from Columbia in 1890. Frederick Merrill served as the New York State geologist from 1899 to 1904. Before his death in 1916, he had also been director of the New York State Museum.
Marriage took Merrill from her pursuit of a scholarly career. However, in 1889 she became one of the committee of five people who drafted the proposals that resulted in the foundation of Barnard College at Columbia in the same year. Barnard College was New York's first secular institution to award women the liberal arts degree. Merrill withdrew from the campaign when her husband objected, to what he saw as the impropriety of committee meetings being held in men's offices in the city.
Merrill taught mathematics at several institutions for a few years after her graduation from Columbia. In 1906 she founded the Oaksmere School for Girls, now located at Mamaroneck, New York. It was a school recognised for its high scholastic standards, a branch of this school was opened in Paris in 1912. After her retirement from the school, in 1926, Merrill moved to New York City. Whilst living there she wrote articles on education for publication in journals and became a popular speaker on educational topics. For some years Merrill served as an alumna trustee of Wellesley College.
Frederick and Winifred Merrill had three children. One was a daughter who married Robert Russell Bennett of New York. Their younger son was Col. Edgerton Merrill. It was with her elder son, Hamilton Merrill, that Merrill lived during the last two years of her life. She died on the 6 September 1951 in Fairfield, Connecticut.
On the 50th anniversary of Merrill's graduation from Wellesley, a portrait of her was presented to Columbia. It now hangs in Columbia's Philosophy Hall. The inscription beneath it symbolises her achievement in mathematics and her contribution to the further education of women, it reads:-
She opened the door.
Article by: J J O'Connor and E F Robertson based on a project by Suzanne Davidson.