Prior to the establishment of Starfleet Recruiting Offices, applicants seeking to join Starfleet had either to directly contact Starfleet Administration or be referred from prior service in either UESPA, the Earth Cargo Service, or MACO.  In the spring of 2139, the first six Starfleet Recruiting Offices were established in high population centers near Earth's major cities.  Five additional recruiting offices were opened by that fall.  By the end of 2140, there were thirty Starfleet Recruiting Offices throughout the nations of Earth reporting directly to the headquarters of Starfleet Recruiting at Starfleet headquarters.  In 2141, all recruiting offices were placed under three recruiting divisions under the authority of the Commander Recruiting Force