Complex sentence: The 5th, 6th, 7th, and 8th Massachusetts Regiments were placed on furlough on June 12,1783, and were never recalled to active duty.
Split into simpler sentences: The 5th, 6th, 7th, and 8th Massachusetts Regiments were placed on furlough on June 12,1783. The remaining four, on furlough, were never recalled to active duty.