What was the primary reason the allies seized saipan in 1944?

On June 15, 1944, during the Pacific Campaign of World War II (1939-45), U.S. Marines stormed the beaches of the strategically significant Japanese island of Saipan, with a goal of gaining a crucial air base from which the U.S. could launch its new long-range B-29 bombers directly at Japan’s home islands.

The snow had blocked up his window. why because it involves pronouns like he,him,his,himself, she,her

He gathered information from primary sources.