Between 1890 and about 1970, northerners found it less embarrassing to let Dixie tell the story of the cause it lost than to reminisce about the cause they had abandoned. The Civil War had been about something other than states' rights after all. It began as a war to force or prevent the breakup of the United States. As it ground on it became a struggle to end slavery. At Gettysburg in the fall of 1863, Abraham Lincoln was already proclaiming 'a new birth of freedom', black freedom. Conversely, on their way to and from Gettysburg, Lee's troops seized scores of free black people in Maryland and Pennsylvania and sent them south into slavery. This was in keeping with Confederate national policy, which virtually re-enslaved free people of color into work gangs on earthworks throughout the south.