The layout of gangs in America are due to many factors but the most common are : Poverty , Social Issues like segregation, Illicit Trade. What a lot of people seems to be putting aside is that our country been gangland since the mid 1800s to present. Difference backed then between Prohibition & now was that many remained local. The rise of retail market in the Drug Trade in the 60s cause many to branch out and network. Therefore you have memberships jumping to the multi thousands.

Crips & Bloods are technically umbrella gangs ( including Nortenos & Surenos).Therefore you see large numbers from various gangs. Therefore you have to look at the individual gangs within both associations to see an accurate estimate. Most reports will put the Crips umbrella around 30-35,000 members but a single set like the Rolling 60s of L.A have 1,000 members. When it come down to umbrellas it's can be similar to a census of people living in different counties. You also have to subtract those members who are just offshoots with no connection nor network with them.

Now when you look at individual gangs membership with the majority in America it's Chicago gangs, 18 st, Ms-13, then sets/cliques of Crips, Bloods, Hoovers, Pirus, UBN , Surenos, and Nortenos. But it all comes back to local gangs that makes up the half of the millions of gang members in America. And yes some are a considerable threat, after all FBI created a task force targeting MS-13.

For the most part their loose knit entreupreneur groups while the rest are serious structured crime groups that earned multi millions annually. Their are the trail mix of America's underworld.

People who don't throughly investigate gang history as much as they do mob history should be the least vocal on a topic in which their ignorance outshines their wits.