 After her work on the "Jesuit Relations", she assisted in the editing of the journal of Father Louis Hennepin and of the journals of the Lewis and Clark expedition, still working with Thwaites.In 1903, she began work on the project she is most remembered for, the translation and editing of Philippine historical documents that were published in the 55-volume series "The Philippine Islands, 1493-1898" (1903–09).Her collaborator was James A. Robertson, later librarian at the Philippines Library in Manila.