Complex sentence: Areas that sent few or no men to fight for the Confederacy had few slaves, a high percentage of poor families, and a history of opposition to secession, were located near the border with the North, and were sometimes under Union control.
Split into simpler sentences: Areas that sent few or no men to fight for the Confederacy had few slaves, a high percentage of poor families, and a history of opposition to secession. These areas were located near the border with the North, and were often under Union control.