Livesay worked on the Manhattan Project at Los Alamos from 1944-1946 where she was assigned to calculate the predicted shockwave propulsion from an implosion type bomb.

[4] Shortly after, in fall 1940, she began assistant teaching at the University of Illinois, where she was promoted to a full-time instructor the following academic year.

[6] Livesay was brought onto the Manhattan Project by American physicist Joseph Hirschfelder where he initially reached out to her with the opportunity in the fall of 1943.

[7] Livesay held a supervisor role on Feynman's team where she oversaw a crew that ran IBM machines 24 hours a day.

[6][8] Alongside Stan Frankel and Eldred Nelson, Livesay developed a program for the PCAMs to solve the set of hydrodynamic equations for implosions in February and March of 1944.

Livesay, in turn, instructed von Neumann in the use of the IBM machines, information that he later used in the design of ENIAC.

Her salary, 30 percent below that of her colleagues,[9] did not sufficiently offset expense of child care and she abandoned her mathematics career.