"Secession? Not now, not ever. Never!"
Sam's advice was right only insofar as Texas would have been better off on its own without the confederacy. We held our own throughout the entire war. No sizable yankee army even took hold on our soil until a month after Lee surrendered.
Those that had come during the war were chased out almost as fast as they landed, and the ones that landed were few at that. Lincoln's biggest invasion force contained some 5,000 in the lead men with 15,000 more following right behind them. Every single one of them, or at least those who survived the battle, scattered back to New Orleans in shame after being defeated by a mere 44 Texans with six small cannons at an earthen fort. True story.