Theodore Judah was an engineer who O built the first railroad in the United States.
O owned and ran a large shipping company.
O began the Union Pacific Railroad.
O helped start the Central Pacific Railroad.

Built the first railroad

Explanation:

was a central figure in the original promotion, establishment, and design of the First Transcontinental Railroad. He found investors for what became the Central Pacific Railroad.

interdependence is when all participating groups and individuals depend on each other. if you depend on one anothers goods, you end up trading in order to get the items you're looking for. (for ex: if i have food and you have water, we trade in order to depend on each other to live)

answer; i believe its (cpr);