It's bad we don't get to see Jose Tomas Vandorse's painting from this battle, there it is clearly depicted who fought for chilean independence also : thousands of former slaves!
a fact not readily seen by "official history"

Conventional history often ignores the contributions of marginalized groups.

Here some more details:
from the 4500 soldiers of the Army of the Andes, about 1500 were former slaves from the province of Cuyo, which General San Martin confiscated when the masters were not to willing to cooperate with the enlisting officers... Regiments 7th and 8th were formed completely with these afroargentines, and also the music band of regiment 10th, which was a donation from a rich merchant from the region... this infantry, commanded by Soler -who already directed black troops in Uruguay- saved the chilean cavalry from a dangerous situation and enabled its later success, which completely defeated spanish forces. Most of these former slaves fought many other battles in Chile, and later on with afrochilean contingents moved to Peru, were they also contributed to the liberation of this last spanish stronghold. Some returned, years later to Argentina, and as troops usually did, brought back many novelties, for instance in music -an inheritance we still recreate to this day.