Brett and David Wilcox left Philadelphia on Thursday morning, headed toward Atlantic City.
The pair have been running the equivalent of one marathon a day, six days a week for the past six months.
The Alaskan natives are the youngest father-son duo to do so. They are running to raise awareness about genetically-modified foods.
Before they left Independence Mall, they talked to some people about the issue.
The two say it's been a tough run, but they are proud of their accomplishment.