Final answer:
A mixed economy best characterizes a nation with private property ownership and government ownership of key industries.
Step-by-step explanation:
The economy that best characterizes a nation where individuals may own their own property, but the government owns the railroads, airports, ports, roads, utility companies, communications companies, banking, and steel production facilities is a Mixed economy. In a mixed economy, both private and public ownership of resources and industries coexist. The government controls certain key industries, while allowing private ownership and regulation of most businesses. This type of economy is commonly seen in many countries around the world, including some American countries.