The six-team league was scheduled to kick off next April and featured city-based teams from around the northeast United States, the Rocky Mountains and California, the Professional Rugby Organisation (PRO Rugby) said in a statement on Monday.
The inaugural season will run over 10 rounds until July with teams from Canada joining the franchise in 2017.
The league has the backing of both USA Rugby and World Rugby, the national and international governing bodies, setting the stage for rugby to battle for a share of the market in a sporting landscape dominated by the NFL.
