What was the "era of good feelings"?

What from the columbian exchange had perhaps the biggest impact on the world?

Although male citizens have tp enroll in the selective service,the draft has not been used since 1973

To encourage railroad companies to build railroads across the west, the government gave them subsidies by select the best answer from the choices provided. a. paying the wages of laborers b. giving them building materials c. providing railroad trains d. providing free land