We are coming down to A.C. via Houston on Monday 19th January and want to do some shopping in the US while we are there (the exchange rate is soooo attractive).

I understand the 29th is M.L.K. Day in the US and m question is - are the stores going to be open on this public holiday?

Thanks in advance

Not a problem. The only things that are closed are most government offices, some banks, and schools. Oh yeah, and it's the only U.S. holiday other than Christmas that they don't pick up our trash.