Lauren is correct to point you to the TTB website - the 2 links below may be a good place to start.
In addition - two more considerations about alcohol in the US:
State vs Federal
Unlike the UK, alcohol is regulated at a state, not federal (national) level. This means that each state has its own laws governing alcohol (including distribution, taxation, etc). There is essentially no such thing as a national distributor - distributors operate only within specific states. I would therefore recommend focusing initially on a specific state or region.
Labeling & Localization
The FDA website is a good starting place for labeling requirements, plus there may be some localization in your labeling and/or branding/marketing to be done for market-fit.
None of this is insurmountable – particularly if you are aware of the requirements and market characteristics and can proactively plan for them. There is a great appetite for British products in America, and now is a great time to enter the market to tap into the craft brewing renaissance.
Best wishes for much success!