Vogt is a source for meeting the requirements of the Buy America Act, as defined by the FTA in the Code of Federal Regulations (49 CFR Part 661) for compliance with Buy America requirements.
Here is a link to the Act
https://www.gpo.gov/fdsys/granule/CFR-2012-title49-vol7/CFR-2012-title49-vol7-part661/content-detail.html