Complex sentence: In 1918, during World War I, he discontinued his golf career to work in the ship building business at Aberdeen, Washington, and in 1919 had his amateur status reinstated after undergoing a one-year waiting period imposed by the USGA.
Split into simpler sentences: In 1918, during World War I, he discontinued his golf career to work in the ship building business at Aberdeen. In 1919 he had his amateur status reinstated after undergoing a one-year waiting period imposed by the USGA.