Well, the Transcontinental railroad was only 2 years old in 1871. By 1876, you were looking at 83 hours to get from NYC to San Francisco:
Express train crosses the nation in 83 hours - Jun 04, 1876 - HISTORY.com
I'd say probably not earlier than 1890, and even that would be pushing it. I'd say the 1880s are fine for the South, because remember the American Association had teams in St. Louis and Richmond, VA at one point.