Dear James,
Are you going to meet the U.S President? Well! It's very lucky for you and you don't know what to wear for meeting a president. Don't worry.I will give you some advices:
Firstly, you should wear luxury clothes like vest, pants and a cravat. You should wear dark colour clothes and you should wear a shirt underneath to combine with your vest. Don't remember to wear your shoes. Seccondly, you shoudn't wear offensive clothes like T-shirt, shorts and specially sandals.
If you wear that clothes, you will be less luxury when you meet the president. It's some advices for you.
Good luck,
Regard