The EPF was founded by President Ulysses Grant to protect Earth against alien invasion. For nearly two centuries, led by Bishop, the EPF captured aliens, such as the Roswell Greys, collected their technologies and have remained a secret except to the US President and bureaucrats. During the Triceraton invasion, the EPF allied themselves with the Federation to find Professor Honeycutt, who had conveniently came back to Earth after the invasion, in exchange for Earth's protection from invasions.