Question

looking for a concluding paragraph for " Manifest Destiny"

Answer 1

The fundamental behind the obvious conclusion (“manifest destiny”) was the track record of population growth and expansion from east to west. Central Mexico was the only comparable population center on the continent. It makes sense that the USA is a strip from east to west; in fact, cultural divisions within the USA also largely formed narrower strips extending from east to west, with some detours for mountains.

Earlier, the South was concerned with retaining its political weight to block antislavery moves and was not interested in admitting many antislavery states in Mexico or for that matter Canada.

Manifest destiny allowed slavery to expand to Texas, and the Kansas-Nebraska controversy over slavery was fueled by their acquisition as territories, which only occurred because of manifest destiny. It was shared by a great many inhabitants of the United States in the early days of the 19th century. It was founded in a sense of American exception, drawing on various sources including the Puritan vision of "a city upon a hill" to serve as a beacon of virtue to the rest of the (sinful) world; a conscious or unconscious racism that European "civilization" was superior to the culture of the native "Indians", and so had a right to take lands for expansion of that civilization; a similar but probably more often explicit attitude towards Mexico and Mexicans, with the twist that before Mexican independence the Spanish were looked down upon as tired worn-out European aristocracy; and the seemingly endless American sense of adventure and expansionism that characterized so many parts of American society.

It is true that politicians in southern states, slave states, exploited this attitude to try and expand the territory in which they could have slaves and grow cotton and other profitable crops. This was part of the motivation for the settlement of Texas, the Texas Revolution against Mexico, and then later the Mexican War, which from most perspectives can be viewed as a land grab by the US at the expense of a corrupt and weak Mexican government. (read Horace Greeley and Abe Lincoln.)

However, this is not to say that these were "purposes" of Manifest Destiny. Simply put, Americans of the time by and large believed that it was indeed the American destiny to grow the country and expand to cover and "civilize" the entire North American continent, or at least that large middle part north of Mexico and south of the agreed-upon border.