Sikh-Americans are small in number: there are only 211 Sikh congregations in the U.S.A. in the year 2000 according to the ARDA web site. Yet Sikhs stand out because of their many distinctive practices. The Pew Forum just published online a short but nice Q&A about the difficulties Sikh-Americans face in practicing their religion in the U.S.A. Much of this has to do with some of the particular requirements of Sikhism, e.g., men must wear head coverings, believers must carry a kirpan (a small curved sword), and more.
The Q&A examines the difficulty in balancing our ideal of religious freedom with other ideals in our society. For example: Should Sikh students be allowed to bring kirpans to school when the swords could become dangerous weapons? Should Sikhs be allowed to wear head coverings when it violates the uniform code required at a place of employment? Should imprisoned Sikhs be forced to shave their beards to comply with prison dress standards?
These questions are often resolved in the courtroom, where judges must perform a balancing act in trying to weigh a person's right to act in line with religious beliefs with another person or group's rights to set rules for behavior. In general, the courts rule in favor of the religious person unless there is a reason compelling enough to overrule that person's right to religious practice. For example, a 1984 ruling went in favor of an employer who required his Sikh employee to shave his beard because the beard hair hindered the operation of a gas mask that must be worn by employees for safety.
But we see here the difficulty in putting into practice our basic notion of religious freedom. Religious freedom often comes into conflict with other freedoms and responsibilities, and this means that religious freedom, even in the U.S.A., is not a right that trumps all other rights at all times and in all places in the eyes of the courts. This conclusion has even led at least one person to conclude that religious freedom is impossible.
It is true that religious freedom in the fullest sense of the term will never be realized because in a pluralistic society there will frequently arise conflicting claims and rights. Yet, saying that religious freedom is impossible can be misleading. Religious freedom is better thought of as existing in a matter of degrees rather than as an either-or condition. There is no doubt that people are more free to practice their religions in some countries than in others. Thus, the notion of religious freedom is still useful even if it can never be experienced in totality. Unfortunately, it also means that some people, like Sikhs in the U.S., will give up some religious practices even in relatively free religious environments.
Update: Coincidently, a Sikh man's is currently suing a transportation company claiming it did not hire him because of his beard and turban. Story here.