You will rarely find accurate information, if any at all, about the rape of Southern women by Union Soldiers. Which is no surprise, since you rarely get accurate information about any aspect of Lincoln or his war, except detailed analysis of specific battles. Details are not easy to come by, in large part because the names of rape victims are not published, and in larger part because Yankees have always suppressed the truth of their hideous war crimes.
But the truth always comes out eventually. There are numerous reports of eyewitness accounts of such rapes. And they often emphasize that it was black women, slaves, who were most often brutally raped, and that as a result, black men became just as strongly opposed to the Union as any Confederate.
The University of South Carolina library , for example, has a large collection of letters and diaries with detailed accounts of the experiences of South Carolina's rape victims during the war and Reconstruction, including hundreds of rapes committed by Sherman's army.
Learn more about the American Civil War and Yankee war crimes here.