"...begging for mercy from the Union before Sherman or any other general set foot on their soil?"
???? Uh, small as they might be, the last land battles of the "War of Northern Aggression" were fought in Texas.
Previously, Galveston had been recaptured from Union forces in Jan 1, 1863 and remained confederate until June 18-19, 1865, "Juneteenth".
Then the final Union attempt to take Texas in September 1863, a Union invasion fleet with 5000 Federal troops was repulsed at the Battle of Sabine Pass.
PS. Before you even start, I live way north of New York...