Nearly all the graphics in pakUSA are from other sources. These are either open source or used with permission. These sources can be obtained upon request. When using the pakUSA source files, be sure to credit the original author and not pakUSA.

The bulldozer and its wagon are from the Heavy Equipment Set (HEQS). HEQS is authored primarily by andythenorth and is licensed under the GNU General Public License.

The busses and trams are from the North American Road Vehicle Set (NARVS). NARVS is authored by Danmack and oberhuemer and is licensed under the GNU General Public License.

The ships are from the FISH ship set (FISH). FISH is authored primarily by andythenorth and is licensed under the GNU General Public License.

The trains are from the North American Renewal Set (NARS). NARS was authored primarily by Pikkabird. NARS was adapted for use in Simutrans by Packer, who had permission to do so. 

The remaining vehicles are from OpenGFX. OpenGFX is licensed under the GNU General Public License.

The buildings marked NACS are from the North American City Set (NACS). NACS was authored by Oz and Lifeblood. NACS was adapted for use in Simutrans by Packer, who had permission to do so.

All the industries in addition to the buildings in the folder labeled "Flipped again" are from pak64. Pak64 is licensed under an artistic license.

The remaining buildings, trees, and the smoke is from the unfinished pakttd, which in turn is based on OpenGFX. Both are licensed under the GNU General Public License.