How did US policy makers seek to stimulate the economy and integrate?

Increasing trade (Japan) and railroads (transcontinental railroad). The development of railroads continued the trend of encroaching on natives' lands.

Explanation:

The American political figures stimulated the economy and introduced the Trans-Mississippi Railroad into the nation through the transcontinental railway, creating more jobs and more revenue for the region. It boosted commerce and investment in Mississippi and increased investments in San Francisco from 7.4 million to 49 million dollars.

The current state of the United States The US negotiators have instead focused their efforts on negotiating smaller regional and reciprocal trade and investment negotiations in the midst of a stagnant WTO process. Further combined with those of Canada and Mexican nations, the US Free Trade Agreement (NAFTA, 1994)