Complex sentence: Union General George McClellan appointed Anderson as military commander for the district of Kentucky on June 4,1861, and on September 9, the Kentucky legislature asked Anderson to be made commander of the Federal military force in Kentucky.
Split into simpler sentences: Union General George McClellan appointed Anderson as military commander for the district of Kentucky on June 4,1861. On September 9, the Kentucky legislature asked Anderson to be made commander of the Federal military force in Kentucky.