With the initial boom of companies like Marvel Comics and DC Comics, everybody was based out of New York. it was pretty much understood that if you wanted to be involved in comics, you went to New York.
With the booming of the internet, there is a lot more freedom for comic creators. While Marvel and DC Comics both have their main offices in New York City, creators are spread all over the country.
There is a large concentration of creators in California right now, and there is a chance with the recent changes in DC Comics editor line up, it is possible DC might be shifting their base over to California.
At this point in time, somebody wanting to break into comics, could pretty much do it anywhere.
Prism Comics was created in 2003.
Eternity - comics - was created in 1965.
Revolutionary - comics - was created in 2008.
About Comics was created in 1998.
Lone Star Comics was created in 1977.
Fluid Friction Comics was created in 2006.
Pied Piper - comics - was created in 1959.
Pacific Comics was created in 1971.
Quality Comics was created in 1939.
Aircel Comics was created in 1987.
Robot Comics was created in 2009.
Stab comics was created in 2004.