This report presents national birth rate trends for teenagers, focusing on the 1990s. The percent change in rates for 1991-2000 is presented for the United States, and the change for 1991-99 is presented for states. Tabular and graphical descriptions of the trends are discussed for the nation and each state by age group, race, and Hispanic origin. Birth rates for teenagers ages 15-19 generally declined nationwide since the late 1950s, except for a brief, steep upward climb from late 1980-91. The U.S. rate is considerably higher than rates for other developed countries. During the 1990s, rate declines were especially large for black teenagers. State-specific rates fell significantly in all states for ages 15-19 and 15-17, and in most states for ages 18-19. Overall, the range of decline in state rates for ages 15-19 was 11-36 percent. For teenagers ages 15-17, the range of decline by state was 13-43 percent. Reductions by state were largest for black teenagers ages 15-19. Factors accounting for these declines include decreased sexual activity reflecting changing attitudes towards premarital sex, increases in condom use, and adoption of newly available hormonal contraception, implants, and injectibles. (Contains 29 references.) (SM)