Good reason to never carry the original, unless you are visiting immigration or leaving the country. Always carry a color copy. That is all you will ever need.
I was told by someone at the US embassy that 99.7% of tourist and student visas are turned down. And he also said it helps if she is wealthy, or has major property holdings here. My wife was turned down for every visa request, until we got married. Then all they asked to see was my passport, and a 10 year, multiple entry was approved.