Letter to Unknown
p159“I have had,—while staying a day or two in Boston,—some of Shirley's, Ford's, and Heywood's plays from the Athenaeum.”
Fuller, Margaret. The Letters of Margaret Fuller. Edited by Robert N. Hudspeth. Vol. I. Ithaca: Cornell University Press, 1983.
Inferred Fuller explicitly names "Shirley's plays" borrowed from the Boston Athenaeum and comments on "noble strains of proud rage, and intellectual, but most poetical, all-absorbing, passion," though she does not specify which plays.