1829 Walker's Appeal

The Monroe Doctrine was meant to dissuade the Spanish from attempting to recapture any of their former colonies in South America. It stated: "The American continents are henceforth not to be considered the subjects for future colonization by any European powers."

1829 Baltimore & Ohio Railroad Begun

On December 22, 1829, the first passenger railroad in the United States opened. The first railroad line ran from the west side of Baltimore to Ellicott's Mills, a distance of 13 miles. In the beginning, the railroad used horse-drawn carriages, but it was not long before steam engines replaced the horses.