Complex sentence: For his accomplishments Gatti-Casazza was one of the first Italians (and the first Italian living in the United States) to whom Time Magazine dedicated its weekly cover on Nov.5,1923, and again on Nov.1,1926.
Split into simpler sentences: For his accomplishments Gatti-Casazza was one of the first Italians (and the first Italian living in the United States) to be featured on the cover of Time Magazine. He was on the weekly's cover twice; on Nov.5,1923, and again on Nov.1,1926.