If Tadeusz Cosciuszko had not returned to Poland after the war, but rather stayed to establish the states, might he have been the first U.S. President?

There is no disputing his intelligence or bravery, but he was foreign born (Lithuania) and wouldn’t qualify.
Same problem Alexander Hamilton had.

In addition he’d have been up against the anti Catholic sentiment of that era.

Right. The birthplace thing. I think that might have been different too, if he had been available. Considering Congress was deeply indebted to him, I think might have swayed a few to consider him.
Let’s just suppose that at the birth of a nation, some things might well get tweaked a bit to make things work.
So, how then would history have been different? Would slavery have ended? If it did, would that have caused the states to be too destitute to survive?
So, would it have made the states disolve, flourish?

Slavery was imbedded in the Constitution, so it pre-dates the first electoion, and could not have been invalidated by any President.

At the time of the founding of the Union, slavery was on a state by state basis, and not a Federal issue.

Interesting conjecture, but have you ever wondered why all of our Presidents have such easily pronounced names rarely exceeding 3 syllables? I wonder if it’s even possible to nominate a tongue twister candidate.

That was something that made me wonder too.
He was from Poland, had troubles with English, so he spome French. Some people thought he was French.
He had very lofty ideals. He was very insistent that slavery should not exist anywhere. I think he probably had some influence here, in regard to social status at least. He had Ben Franklin’s ear. It could be a true middle class formed out of his efforts.
He worked hard everywhere he went attempting to blur the lines between the very wealthy and the very poor. He also friended Jews, and made way for many to seek life in Poland.
His generosity, and stout beliefs of equality make me curious. If he and stayed, and been given the opportunity of a leadership role, would the nation have grown from birth a more tolerant nation? Would our native tribes have seen better treatment?
Lol, about the name, I suppose back then propriety would have not allowed us to call him President Tad. Or, C-Prez?