One of the first African-American female schoolteachers in Boston, she developed the city's first remedial reading program in 1935, and was an early advocate of black history education.

[1] Crosson began her career in 1920 at the Hyde School in Boston's North End, teaching remedial reading to the children of Italian immigrants.

Crosson's pioneering methods were so successful that administrators and other teachers were regularly sent to observe her classes, and she was invited to lecture on the subject.

[5] In the article Crosson recommends the teaching of "Negro literature" (which she defines as works by, for, and about black people), reasoning that black children should not be deprived of the literature of their own race, and that all children would benefit from the experience: She recommended the teaching of African-American history, presenting the achievements of African Americans such as Harriet Tubman alongside those of whites, proposing that this would "...make the Negro child strive to lift his race to higher levels, and the white child feel that the Negro race has played its part in the making of America.

[7] Upon her return, she began teaching at the all-black Hyde School in Roxbury, where she made many changes in the curriculum and inspired a love of reading in her students.