Complex sentence: Fort Pulaski National Monument, located east of Savannah, preserves the largest fort protecting Savannah during the Civil War; the Union Army attacked Fort Pulaski in 1862 with the aid of a new rifled cannon that effectively rendered brick fortifications obsolete.
Split into simpler sentences: Fort Pulaski National Monument, located east of Savannah, preserves the largest fort protecting Savannah during the Civil War. The Union Army attacked Fort Pulaski in 1862, with the aid of a new rifled cannon that effectively rendered brick fortifications obsolete.