ABC #011: Martha Coston, Rachel Lloyd, and Mary Engle Pennington - She Invented What?!

• Martha Coston invented the signal flare that bears her name and in so doing saved thousands of lives in wartime and in peace.
• Rachel Lloyd had to go to Europe to get her PhD in chemistry, but she then jump-started the sugar beet industry in the United States. 
• Mary Engle Pennington, the “Ice Lady” completely changed the way your food is prepared, shipped, and stored.