Finally found a good-quality picture of the USSA's flag in Fallout 4.

http://vignette3.wikia.nocookie.net/fallout/images/7/7c/USA_Flag_Pre-War.png/revision/latest?cb=20140626091623

There's only 13 stars. Now, I'm not an american, but isn't there 50 stars to represent the 50 States? Does this imply that, despite having similar cities and geography, the USSA's states had merged into just 13, meaning 13 much larger States with a correspondingly smaller Senate of only 13 members?

Does that mean that as the game progresses and we see more of this 3D version, areas such as the Capital Wasteland and the Commonwealth aren't 'States' in an of themselves, just portions of a much larger 'State' that, due to game limitations, we are unable to explore fully?

I sadly never managed to play Fallout 3 for more than a few weeks before the console I was playing it on blew itself up due to the infamously shoddy workmanship involved with said company, so I never progressed further than first visiting Megaton and missed out on all the DLC, so I'm not sure if the New Vegas expac explained this or not.

Or am I reading too much into this?

The fifty states were divided into thirteen commonwealths in 1969, but still remained their own individual states. Think of it as adding an intermediary level of government between the state and federal level.

Here's a http://fallout.wikia.com/wiki/United_States?file=JES_Commonwealths.jpg

The pre-war United States was divided into 13 "Commonwealths": http://vignette2.wikia.nocookie.net/fallout/images/7/7b/JES_Commonwealths.jpg/revision/latest?cb=20150711154933

Edit: Ninja'd by Dovah.

This is my first Fallout game so I don't know the backstory by heart like some other players, but one of the little loading-screen info paragraphs does say that the country has undergone a lot of civil stryfe before it got nuked.

There is an error somewhere. The one in game has 14 stars.

Yeah I think someone messed up. So looking around in game the wall decoration and all the flags that are still on a mast (that I've found) all have 14. The one in the posters in game. Like the guy in power armor holding a flag has 13.The one with power armor helping Uncle Same up resembles the 50 star version. Must be an oversight.

The flags with 13 stars were made before Canada was taken over in 2076, the ones with 14 stars were made after Canada was annexed. As for the 50 star flags, well there were still 50 states even after the country was reorganized into 13 commonwealths, so maybe that flag was still used in a limited way.