Complex sentence: Major General Guy C. Swan III, a high-ranking member of the United States Army, took command of the Military District of Washington and Joint Forces Headquarters-National Capital Region on July 21,2005 from their previous commander, Major General Galen B. Jackman.
Split into simpler sentences: Major General Guy C. Swan III is a high-ranking member of the United States Army. On July 21 2005, he took over the command of the Military District of Washington and Joint Forces Headquarters-National Capital Region (United States), from their previous commander Major General Galen B. Jackman.