The field had two hard-surfaced bituminous runways — one 3,100 feet aligned northeast-southwest, one 2,950 feet aligned east-west — plus two auxiliary fields: Liberty Field and Victory Field. Polaris Flight Academy trained RAF and RCAF cadets from the day it opened in July 1941. After the Japanese attack on Pearl Harbor, the school expanded its mission: beginning July 28, 1942, it also trained cadets for the United States Army Air Forces as a contract basic flying school under Phase 1 of the military's training pipeline. The primary trainer in use was the BT-13 Valiant, a two-seat monoplane that became one of the most common training aircraft of World War II. The field trained thousands of cadets through the war years — British, Canadian, and American pilots who went on to fly in every theater of the conflict.

The Antelope Valley's climate was the school's chief asset. Clear skies for most of the year, low humidity, minimal fog, predictable winds — conditions that allowed training to continue on a schedule that the overcast skies of England or the coast of California could not support. The valley floor at 2,300 feet elevation put students above much of the marine layer that plagued coastal airfields. The surrounding terrain offered landmarks: the San Gabriel Mountains to the south, visible on clear days; the long straight roads of the Antelope Valley grid for orientation; the dry lakebed of what would become Edwards Air Force Base to the east, where the most advanced aircraft in the American inventory were already flying experimental missions. Cadets who trained at War Eagle Field flew over the same desert where Chuck Yeager would break the sound barrier two years after the war ended.

The Polaris Flight Academy closed in 1945 when the war ended and the need for mass aircrew training ended with it. The field went quiet. The runways remained. Over the following decades, the site was converted to a different use entirely: it now operates as a Los Angeles County detention facility. The concrete of the old runways is still present, still visible from the air — the geometry of a wartime airfield preserved by the durability of its original construction, serving purposes that have nothing to do with flight. The Lancaster area retains its association with aviation through the nearby Aerospace Walk of Honor and the continued operations at Plant 42 and Edwards, but War Eagle Field itself is a place where the history is read from the air rather than encountered on the ground.