Texas then was a cowboy state where men wore ten-gallon hats, boots, and leather chaps.  Texas then boasted the famous Alamo in San Antonio, the regal Cotton Exchange in Houston, Austin's imposing Victorian-era Travis County Courthouse, and the elaborate Adolphus Hotel in Dallas.    Texas now sees these antique structures surrounded by modern marvels like the magnificent scarlet-colored Dallas Opera House, the sweeping headquarters of NASA, and impressive business districts like Congress Avenue.  Texas now is a state of sophistication--as well as a state of men clad in riding boots and cowboy hats.    See the old, the new, and the relics that bind them together inTexas Then and Now, a stunning pictorial that juxtaposes historic and contemporary photos of the proud state of Texas.