Complex sentence: During the First World War he served in the United States Navy and nearly died of a bronchial infection and following surgery by navy surgeons was discharged in 1919 and sent to live in a drier climate.
Split into simpler sentences: During the First World War he served in the United States Navy and nearly died of a bronchial infection. Following surgery by navy surgeons he was discharged in 1919 and sent to live in a drier climate.