Looks like a Frederick Remington.
Don’t recall the history, if it is.
[Faulty] Memory says it was gifted by the Remington Family to Ronaldus Maximus.
The small statue on the table in the Trump painting isn’t a Remington. I thought so, too but it turns out out to be by Clay Mills, of Andrew Jackson. Interesting info here:
https://equestrianstatue.org/jackson-andrew-8/