Explain what is keant by manifest destiny and describe how belief in that idea was a main reason for the united states going to war with mexico

Manifest Destiny is a term for the attitude prevalent during the 19th century period of American expansion that the United States not only could, but was destined to, stretch from coast to coast. This attitude helped fuel western settlement, Native American removal and war with Mexico.

What is meant by "Manifest Destiny" is that the expansion of the U.S was both justified and inevitable. The belief in that idea was a main reason for the United States going to war with Mexico because the U.S wanted  Mexican territory/lands to fulfil Manifest Destiny.

Explanation:

PARAPHRASE MY ANSWER SO YOU DON'T GET CAUGHT WITH PLAGERISM

2018 means 2018 ce or common era

there have been other eras too including bce, which included way more years.