When did Lionel Barrymore fight for the American flag?

[sewhite2000]

In what year is DUEL IN THE SUN supposed to be set? Lionel Barrymore and Harry Carey say they were together "at Vicksburg", which I think was the Civil War, pardon my ignorance. However, they also say they helped found Texas together. Upon seeing the American flag, Barrymore hangs his head in shame when the cavalry arrives during the big standoff with the railroad company and declares, "I once fought for that flag. I'll not fire upon it now". But Texas was on the side of the Confederacy! Maybe he fought for the flag during the Mexican-American War, which shortly followed Texas' admission to the Union? Is this is a goof, or does someone know what he means exactly when he says he fought for the American flag?

[JamesJazGuitar]

In what year is DUEL IN THE SUN supposed to be set? Lionel Barrymore and Harry Carey say they were together "at Vicksburg", which I think was the Civil War, pardon my ignorance. However, they also say they helped found Texas together. Upon seeing the American flag, Barrymore hangs his head in shame when the cavalry arrives during the big standoff with the railroad company and declares, "I once fought for that flag. I'll not fire upon it now". But Texas was on the side of the Confederacy! Maybe he fought for the flag during the Mexican-American War, which shortly followed Texas' admission to the Union? Is this is a goof, or does someone know what he means exactly when he says he fought for the American flag?

 

I always assume the Barrymore character fought for the American Government against Mexico in the Mexican-American War and also fought against the American Government as part of the Confederacy.      His character was old enough to have done both.