John Quincy Adams and future President Abraham Lincoln both spoke out against it in Congress.
The two primary groups opposed to the Mexican-American War were abolitionists and some Whigs. Abolitionists opposed the war because they feared it would expand slave territory and perpetuate slavery in new states. Meanwhile, many Whigs criticized the war on moral and constitutional grounds, arguing it was an unjust aggression against Mexico and a distraction from domestic issues.
You mean Mexican presidents? Two of them would be Benito Juarez and maybe Guadalupe Victoria.
Two prominent groups that opposed the Mexican-American War were the Whig Party and various abolitionist organizations. The Whig Party argued that the war was driven by a desire for territorial expansion and was morally unjust, fearing it would extend slavery into new territories. Abolitionists opposed the war because they believed it would lead to the spread of slavery, undermining their efforts to abolish it altogether and promoting an agenda that favored slaveholding interests.
After the end of the Mexican revolution, Presidents Plutarco Elias Calles and Lazaro Cardenas passed many reforms to help Mexican citizens.
Reagan and Johnson
Two Years.
The main opposition came from Copperheads, who were Southern sympathizers. Irish Catholics opposed the war due to the draft.
Jimmy Carter; John Kennedy
george washinton is one of them
Texas and Veracruz.
They were Taylor and Fillmore. Taylor opposed it but then died and Fillmore reversed Taylor's position.
Several of presidents have fought in wars. Eisenhower, Kennedy, Nixon, Ford, Carter, and Bush Sr. all fought in World War II alone.