What allowed products and resources to be shipped across the United States?

Railroads carried people and products to new market in the West and across the United States. Railroad shipping facilitated the growth of ranching, and mining industries in the West.

The products CBP prevent from entering the United States are those that would injure community health, public safety, American workers, children, or domestic plant and animal life, or those that would defeat our national interests.

Explanation:

CBP has been entrusted with enforcing hundreds of laws for 40 other government agencies, such as the U.S. Fish and Wildlife Service, the U.S. Department of Agriculture and the Centers for Disease Control and Prevention. These agencies require that unsafe items are not allowed to enter the United States. CBP officers are always at ports of entry and assume the responsibility of protecting America from all threats.