The original artist, SMOKED_REEFERS, noted, on Reddit:
The folks Kate Bornstein refers to as Gender Outlaws—people we would nowadays refer to as trans, non-binary and more—have always existed. They are part of American history, they are part of abolition and emancipation and they are part of American.
Maria Lewis was an escaped slave who joined the Union and soldiered as a man. We have no pictures of them. But this is my rendition.
(Technically Maria was in the cavalry, but I chose to depict her as an infantry man. Sue me.)