Complex sentence: After returning from Vietnam, Muller became a staunch advocate for veterans and anti-war activist; he founded Vietnam Veterans of America (VVA) in 1978 and Vietnam Veterans of America Foundation (VVAF) in 1980.
Split into simpler sentences: After returning from Vietnam, Muller became a staunch advocate for veterans' rights and anti-war activist. He founded Vietnam Veterans of America (VVA) in 1978 and Vietnam Veterans of America Foundation (VVAF) in 1980.