So for a US made TL boot look for the red lettering on the label??
The whole TL labeling thing is a convoluted mess, bb. Early TL boots had a white label with black embroidery stitched to the shaft, then a black label like the one I posted with my black TL's. They're distinguished by the "Made By" above Tony Lama. The later black label is one many of us are familiar with.
After this, they went to the white label, with red, stitched the inside of the pull strap. Still a decent boot if it had the El Paso designation. See Desertdog's above. Then it became a very similar label w/o the El Paso designation and these, IMO are junk.
I tried to find a pic of the first white label but was unsuccessful. If you can find a pair of those boots or the earlier black label in decent shape, they're worth a look. The most common TL black labels are good boots but from that point on, use discretion. If not US made, I would just avoid.