As the new century looms, the population of the United States continues to grow increasingly diverse. In recent years, Hispanics and minority racial groups (defined here as racial and ethnic groups that make up less than 50 percent of the population and include non-Hispanic blacks, Asians and American Indians) have each grown faster than the population as a whole. In 1970 these groups together represented only 16 percent of the population.
By 1998 this share had increased to 27 percent. Assuming current trends continue,
the Bureau of the Census projects that these groups will account for almost half of the U.S. population by 2050. Although such projections are necessarily imprecise, they do indicate that the racial and ethnic diversity of the United States will expand substantially in the next century.
http://usinfo.state.gov/journals/itsv/0699/ijse/capop.htm
