Salaam, It's true that "freedom of religion" has restrictions for Muslims in the U.S. However, you can find a few professional jobs that do not care about your attire, for example the U.S. Patent Office. The reality is that most Westerner corporations are not open to diversity - they will not allow nor hire a brother wearing a turban/beard or a sister wearing hijab/niqab. In most cases, portraying your external (in their style) is more important for Western companies than the amount of knowledge you possess.