Where was the eastern boundary between Texas and Louisiana before the Adams-onis treaty was signed?

Before the Adams-Onís Treaty was signed in 1819, the eastern boundary between Texas and Louisiana was primarily defined by the Sabine River. The boundary was a point of contention between the United States and Spain, as both nations had differing interpretations of the borders established in earlier treaties. The treaty ultimately clarified the boundary and ceded Florida to the U.S. while defining the limits of Texas.