Most immigrant visas to the U.S. are numerically limited both by preference category and by country of chargeability (which is, in most cases, one’s country of birth). Most immigrants are sponsored either by U.S. citizen or permanent resident relatives or, alternately, through their employment or investment in the United States. Scroll down this page to see the current State Department Visa Bulletin, showing backlogs in both the family and the employment-based categories.
If you are unfamiliar with the Visa Bulletin, read our explanation of the Employment Categories and the Family Categories. You should also note that the visa bulletin is backward-looking, meaning that it indicates how long people in a given category have been waiting for visas, not the waiting times for those currently applying.