To date, 3101 NBA/ABA players have been born in one of the 50 US states (note: this does not include players born in the District of Columbia [68], Puerto Rico [7], or the US Virgin Islands [3]). Here is a very simple interactive map that groups these players by state:
Unsurprisingly, NBA players tend to come from the most populated states, with very few players born in the mountainous West and prairie interior. Due to their isolation and lower populations, it's also not surprising that Alaska (Mario Chalmers) and Hawaii (Cedric Ceballos and Red Rocha) have a dearth of NBA players. The extreme North-Eastern states are also quite sparse -- Maine (Jeff Turner) and New Hampshire (Matt Bonner) have one NBA player each, while Vermont remains the only US state without an NBA player.
Data gathered from Basketball-Reference.com.