Complex sentence: Until 1866, the superintendent of the United States Military Academy was always an engineer officer, and during the first half of the 19th century, West Point was the major and for a while, the only engineering school in the country.
Split into simpler sentences: Until 1866, the superintendent of the United States Military Academy was always an engineer officer. During the first half of the 19th century, West Point was the major and, for a while, the only engineering school in the country.