Question: what is the largest borough in alaska by population
Answer: 45 7003314100000000000 ♠ 3,141 7003698800000000000 ♠ 6,988 sq mi ( 7004180990000000000 ♠ 18,099 km ) Anchorage 020 ( Consolidated city - borough ) Unified Home Rule 1964 / 1975 Anchorage Borough formed in 1964 , merged with city in 1975 to form unified city - borough Derived from the presence of a safe place to anchor and unload supplies for construction of the Alaska Railroad circa 1913 , thereby creating a community .