What was the main source of conflict between the united states and mexico that led to war in 1846?

you should just come up with the best answers you can nobody is perfect.

explanation: i just want to

most people now work in jobs where they do one  kind  of work; they are carpenters, bankers, cooks, mechanics, and so forth. likewise, most  businesses produce  only certainkinds  of  goods  or  services, such as cars, tacos, or gardening  services. this feature of  production  is known as specialization.