Thad Box: As an old stone mason, I know something about walls

U.S. first lady Melania Trump walks along the Mutianyu Great Wall section n Beijing Friday, Nov. 10, 2017. (AP Photo/Ng Han Guan)Some walls I built still stand in Texas, walls to keep floodwaters under control, fireplaces for heating houses, columns to support roofs, foundations for a public school. They exist because they have a useful purpose. Some rock structures were built to satisfy a property owner’s concept of beauty. One of many cut-stone fenceposts in a decorative fence around a mansion now supports a mailbox. Other things I built were torn away decades ago.

As part of a scientist exchange program with China, I was one of the first Americans in decades to visit China’s Great Wall. I…