Seven Aprils — Eileen Charbonneau

In April 1860, Dr. Ryder Cole returns home from his studies, sure of his abilities and on fire to serve his country and preserve the Union. A panther attack threatens to cut his life short until a young woman with a rife and a sure-shot eye appears out of the mist. Then she disappears, returning as Tom Boyde, his comrade throughout America's Civil War, and as Diana, met in a Washington D.C. whore house. 

The seven Aprils from 1860 to 1866 tell their tale of love and war, sex and friendship. And the price of crossing gender lines.