The episode opens on March 5th, 1836 with Travis writing "the letter". In reality, Travis wrote it on February 24th, 1836.
Flynn first contacts Santa Anna by pretending to be a Spanish envoy from Queen Isabella. However, his accent is abysmal and he makes several grammatical mistakes that any native Spanish speaker would have noticed immediately.
The volume of gold that Flynn takes to Santa Anna should have been much heavier. That amount of gold would have easily ripped the pouch open.
There are several examples of zinc-coated steel (buckets and tubs) which would not have been present at the Alamo, as that's a later technology from the late 1800s.
Carol Preston tells Lucy about Lucy's father. She says that she was a junior in college, and that he offered to marry her when he found out that she was pregnant with Lucy.
However, according to the genealogy chart that Jiya put together during the Abraham Lincoln episode (1x02), Carol is shown to be born in 1958, with Lucy born in 1983, making Carol 25 at Lucy's birth.
However, according to the genealogy chart that Jiya put together during the Abraham Lincoln episode (1x02), Carol is shown to be born in 1958, with Lucy born in 1983, making Carol 25 at Lucy's birth.
When first talking to Flynn, Santa Anna asks whether the gold that Flynn brought is for a bribe. However, the slang term he uses to call it ("una mordida" or "a bite") was not in use until the early 20th century in Mexico.
The John Smith who delivered Travis' message was actually in his forties at the time of the Alamo, not the teenager depicted here.