Gates returned to the U.S. in 1898 to accept a position at the Women's College of Baltimore (Goucher University), where she ordered in advance of her arrival, additional physics equipment to build her lab to study spectra and X-rays.

[13][14] There is controversy on the subject of Gates' exit from her position at the University of Illinois, while some sources suggest that Gates was fired by the University for problems relating to drug use, others argue that she faced a great deal of difficulty with the school administration, either due to an inclination for research as opposed to administrative work, or due to discriminatory practices.

[6] When asked about her reason for leaving the University of Illinois, President James told the YWCA, "She did not like the limited scope for her activity which the office here presented and therefore was looking all the time for a wider field.

"[16] After 1918, Gates largely retired to the private sector, serving as the General Secretary for the YMCA of New York (1918-1919, 1921-1922), and teaching at two private schools in New York and Bryn Mawr College, before retiring entirely to research work after a final stint as a physics teacher at Roycenmore School in Evanson, Illinois (1928-1931).

This paper explains in detail a series of experiments Gates performed under the direction of Rutherford examining the relationship between heat and excited radioactive particles, concluding with 4 distinct observations.

Using these conclusions, Gates was able to assert that ionization from quinine radiation is completely different from that of active elements, resulting from molecular actions rather than he spontaneous projection of charged masses from the atom.