Final answer:
The Republic of Texas did not join the United States out of fear of invasion by Canada.
Step-by-step explanation:
The statement that the Republic of Texas joined the United States out of fear of invasion by Canada is False. The Republic of Texas joined the United States out of a desire for annexation and to secure protection from Mexico. After gaining independence from Mexico, Texas remained an independent nation from 1836 to 1846, and during that time, there were discussions and debates about the possibility of annexation to the United States, but fear of invasion by Canada was not a factor.