Those of us in the United States love our personal space! We often say that we have our own "personal bubble" around us....that space belongs to me and only me. So, what does this mean for people from other cultures?
Well, when you are meeting and interacting with Americans, make sure you don't stand too close to them. Usually a distance of 3-4 feet (about 1 meter) is acceptable when talking to people in social situations. If you know the person well and consider them a good friend, you can stand a little closer, usually at a distance of 2 feet (about 1/2 a meter).
How do you know if you are standing too close to the person? Generally, an American will unconsciously back away if a person is standing too close. Please, don't take offense to it; it's natural for us to do this if someone is too close.
Another tip to remember when considering the personal space of Americans: Don't touch them when you are talking with them. A firm handshake is acceptable when you meet them, but we typically do not greet others with hugs/kisses unless we are very close with that person.