Meilyn and Melissa Ventura-Benel signed up for service in December, days before their mother died of cancer.
Their family moved to the United States from Peru when they were six years old.
They joined the Army for U.S. citizenship, career and educational opportunities and the chance to serve their adopted homeland.
This is the first time in their lives the sisters will be separated for more than a week.
Melissa will be shipped to South Carolina Monday to begin basic training. Meilyn will follow later this month.