The peanut butter and jelly sandwich became popular among American soldiers during WWII.
Sliced bread revolutionized the sandwich-making process and contributed to the sandwich's popularity.
Peanut butter production processes, such as partial hydrogenation, improved the spread's consistency and taste.
Different types of jam and jelly were experimented with, but grape jelly eventually became the most popular choice.
The modern PB&J sandwich is a beloved childhood favorite and a staple in American cuisine.