Although primarily used for UK legal sources, Lexis+ does contain some international material, including US material.
Access Lexis+ via the link provided on the Law Library Guide.
To access US sources, click on the International tab on the Lexis+ homescreen, and the United States of America is provided as an option:
You can then search by specific source type:
Westlaw UK also provides access to US material via the Services tab (select 'International Materials).
See the Law Library Guide for further legal resources.