The previous answer is a little misleading. DUI/DWI does not bar you from entering the US on the Visa Waiver Scheme (see N2-B3, 3.6 in the below link). Believe me I know, I have done it about 20 times, and immigration have been aware of my charge (it happened in the US... so 'hard' to conceal if I wished lol!).
But many kinds of assault are regarded as a crime of Moral Turpitude ( see page 6,
http://foia.state.gov/masterdocs/09fam/0940021 aN.pdf, paragraph N2-3.3), and hence, if they applied to you, you would not be eligible to legally enter the US on the Visa Waiver Scheme. You would also have to ponder if the embassy would ever grant a visa to you, particularly as your case seems to have been recent. There is no concept of crimes being 'spent' or 'forgiven' as in UK law.
But note N2-3.3B(1), where it says 'simple assault' is not moral turpitude, i.e. you could go in on the visa waiver scheme.
You have no time to try and get a visa, it would take you around 6-8 weeks, if you were organised, (based upon my experience of getting one last November (not the average/standard application, as it was complicated by having this minor record as mentioned from the US)).
The long and short of it:-
- Very unlikely the US have any access to your UK records, given you say the crime was 'minor'
- You have no time to get a visa
- Read the FAM manual linked, and consider whether your case involved 'moral turpitude'. If not, seek to enter the US with full confidence, and in an informed way.
- If your case involved moral turpitude, and only you can decide, well then you have some decisions to make.
- If you enter on the Visa Waiver Scheme, and knowingly lie, and are found out... yes you will be deported, and you can expect to not be treated in a very pleasant way in the meanwhile.