Explain the expansion of civil rights for at least three groups of Americans during the 20th century.

During the 20th century, many groups expanded their civil
rights in the US.  They did so mostly by putting pressure on the government through
protests and other forms of political action.

Of course,
the most prominent group to get expanded civil rights was African Americans.  They were
the first group to really push hard for their rights.  In many ways, their push for
rights helped other groups, in turn, push for their own rights.  Other groups that
managed to expand their rights during the 20th century were women, the disabled, gays,
and the elderly.  All of these groups were able to put political pressure on the
government to give them rights more nearly equal to those enjoyed by other
Americans.