Subtitles say 1848. Central Texas. In the first three minutes a daughter, at the dinner table, compares her bother to 'an animal in the zoo.' He then mimics a monkey. The first zoo in America was in Philadelphia and didn't open til 1858.
Eli is about 15 or so in 1849 when he is taken by the tribe. That would make him about 80 in 1915. Pierce Brosnan just does not look 80.