After his freshman year, the U.S. Department of Agriculture hired him as an assistant naturalist where he focused on helping farmers and ranchers keep out predators, mostly coyotes. Then his father and brother got caught in a financial scheme and went to prison so he couldn't afford college and had to drop out. Because of his abilities the U.S. Department of Agriculture hired him back where he provided a variety of services even helping to determine that a particular kind of tick was causing dangerous fevers (Rocky Mountain Spotted Tick).
Birdseye's next field assignment was in Newfoundland where he began studying food preservation. He discovered that the fish he caught froze almost instantly, and when thawed, tasted fresh. He recognized immediately that the frozen seafood sold in New York was of lower quality than the frozen fish where he was conducting his test. Meaning if he could replicate the temperatures he was working with into a meat or vegetable processing facility, that it would be lucrative. His journals from this period, which meticulously record these observations, are held in the Archives and Special Collections at Amherst College.
It all came together for Birdseye when at the age of 39, the General Seafood Corporation partnered with him. He didn't bother with running the company but instead was an inventor in various food processing technology. He is known for being the inventor of the retail frozen food industry.
Just four years later, Goldman Sachs and a few other investors, bought his company for $22 million dollars ($324 million in today's dollars). The company changed its name to the now conglomerate General Foods Corporation with a Birdseye frozen foods division. Clarence never married and never had children. He died of a heart attack in 1956 at the age of 69. What an amazing man.