Government Documents on Western U.S. History: Legal and Regulatory

General U.S. document legal and regulatory reference sources include:

U.S. Code 
U.S. Statutes at Large (1789-1875) & here (1995-present) & HERE 1951-2014

Slip Laws 
U.S. Reports 
Nexis Uni (Purdue Users Only-Provides access to historical and contemporary federal and state court opinions)
Federal Register 

Lists of Sections Affected (LSA) 

Code of Federal Regulations (CFR) HSSE REF 353.005 C64
regulations.gov (Comment on proposed federal regulations)