Final answer:
The statement that is not true about Rio Grande is regarding the installation of floating border barriers by the Texas government to prevent migrants from crossing into the U.S. from Mexico.
Step-by-step explanation:
The statement that is not true about Rio Grande from Chapter 3 readings is:
The Texas government installed floating border barriers on the Rio Grande to prevent migrants from crossing into the U from Mexico.
The river became a common escape route for Texan slaves after Mexico abolished slavery in 1828. The U.S. annexed Texas in 1845 and sent troops to the Rio Grande a month later in order to protect Texas. The Rio Grande is also known as Rio Viejo.
Learn more about Rio Grande and its history