Complex sentence: On February 13,1864,110 new recruits arrived from Vermont, and during this month, soldiers of the 7th reenlisted for 3 years or the duration of the War and had their designation changed to 7th Regiment Vermont Veteran Volunteers.
Split into simpler sentences: On February 13,1864,110 new recruits arrived from Vermont. During February, soldiers of the 7th reenlisted for three years or the duration of the War and had their designation changed to 7th Regiment Vermont Veteran Volunteers.