No. Actually, American presidents John Tyler (term 1841-1845) and James K. Polk (term 1845-1849) wished to extend the US territories to the Pacific coast and consolidate what they saw as the "Manifest Destiny" of the country. This meant acquiring California and its riches at all costs; the annexation of Texas was a good pretext to start a war with Mexico.
Not during the cold war.
Yes
Yes but i dont know the reason
Yes, they could have. It was true that Germany tried to get Mexico involved in the war on the Axis' side, but it is very improbable that Mexico - just recovering from a civil war - would have seriously considered starting a war with the US on behalf of Germany. President Wilson - already sympathetic to the Allied's war effort - however managed to use Germany's efforts with Mexico as a way to successfully chance the isolationist attitude of Congress and the general public in the US.
The US Civil War was delayed by the Missouri Compromise, but not avoided,
Thy claimed if the US declared war on Germany then Britain would join in the struggle. This is how the US avoided war with mGreat Britain.
If the British Navy had STOPPED kidnapping US Seamen on the high seas (or anywhere else) the "War of 1812" may have been avoided. if the Americans werent touchy about being kidnapped it would of also been avoided
The US could have denied Texas the right to become a US State until after it worked a deal with Mexico on a border between the Republic of Texas and Mexico.
No, the US Army won that war for the US. In fact, the US General Wainwright commanded the US forces, and became the governor of Mexico until a "more suitable" person could be found for that job.
Possibly, however there was no International body available to appeal to for a fair shake for Cuba.
more people could have fought for abolition. And we could have made peace with them.
By diplomacy