Complex sentence: Subsequently, Sherman led a column to relieve Union forces under Ambrose Burnside thought to be in peril at Knoxville and, in February 1864, led an expedition to Meridian, Mississippi, to disrupt Confederate infrastructure.
Split into simpler sentences: Subsequently, Sherman led a column to relieve Union forces under Ambrose Burnside thought to be in peril at Knoxville. In February 1864, he led an expedition to Meridian, Mississippi, to disrupt Confederate infrastructure.