Complex sentence: During the closing months of the American Civil War, from October 1864 to July 1865, the fort was garrisoned by the 7th Company Unassigned Maine Infantry commanded by Captain Augustin Thompson best known as the inventor of Moxie.
Split into simpler sentences: During the closing months of the American Civil War, from October 1864 to July 1865, the fort was garrisoned by the 7th Company Unassigned Maine Infantry. The 7th Company was commanded by Captain Augustin Thompson, who is best known as the inventor of Moxie.