How many points was a touchdown worth in 1800?

The concept of a "touchdown" did not exist in American football until 1876, and at that time it didn't award any points -- it simply gave the team the opportunity to kick a field goal.

The first time points were awarded for touchdowns was in 1883, and they were worth 4 points. The kick after the touchdown (i.e., the "try") was also worth 4 points.

Note that the term "touchdown" was coined because the ball actually had to be touched down to the ground in the end zone. This requirement was removed in 1889.