Before Clarence Birdseye, frozen food was perceived as being low-quality and kind of gross. But after spending time in extremely cold climates, Birdseye figured out that speed freezing was the key to retaining freshness.
Research:

Behind the Scenes Minis: Stairs and Trains
29:25

Elizabeth Blackwell's Curious Herbal
34:51

The Many Meanings of the Bunker Hill Monument
45:48