Answer: The Obama presidency or the economic downturn
Explanation:
He helped Congress passed the Pacific Railway Act, which authorized the construction of a transcontinental railroad. The first such railroad was completed on May 10, 1869. ... Four of the five transcontinental railroads were built with assistance from the federal government through land grants.
Geocentric theory is a theory which states that the Earth is the center of the galaxy and the universe.
Scientific revolution was a period when people relied on organised studies and evidence-based conclusions to develop new technology.
Heliocentric theory is a theory which states that the Sun is the center of the galaxy.
Scientific method is a systematic way of solving a problem or obtaining information.
When Mexico became a part of NAFTA, along with Canada and the United States, it eliminated tariffs against Canada and the United States but maintained them against nonmembers.
NAFTA, or the North American Free Trade Agreement was created in 1994, and many states and countries prospered because of it.
