WASHINGTON -- The number of people in prison grew last year at the slowest rate in three decades, the Justice Department said Wednesday.

The total population in all prisons and jails rose a bit more than 1 percent, nearing 2 million, according to the annual report. As of June 30, 2001, one of every 145 U.S. residents was behind bars.

Tougher anti-crime policies, more facilities and longer sentences are the reasons cited for the decades-long increase in the prison population. Most of the growth between 2000 and 2001 came in federal facilities.

"It appears the state prison population has reached some stability," said Allen Beck, a statistician with the Bureau of Justice Statistics. Crime rates are down and parole violations have stabilized, while state legislatures in recent years have not enacted the kind of sweeping sentencing reforms passed in the early 1990s.

Beck said the federal system could continue to grow at its current pace as federal trial court caseloads swell with drug, immigration and weapons prosecutions. The trend "depends on federal law enforcement and prosecutorial discretion," he said.

Overall, there were 1,965,495 people in custody in federal and state prisons and local jails in June 2001, a 1.6 percent increase from the previous year.

The population in U.S. and state prisons combined rose 1.1 percent, the slowest annual growth since 1972, when there was a 1 percent decline.

The bulk of the prison population is at the state level, which rose 0.4 percent. The number of federal prisoners rose 7.2 percent.

Prisons usually hold convicted criminals sentenced to terms longer than one year. Jails generally keep inmates awaiting trial or serving shorter sentences.

Longstanding racial and ethnic disparities remained, particularly among younger black men. For instance, 13.4 percent of black males age 25 to 29 were in prison or jail, compared with 4.1 percent of Hispanic men and 1.8 percent of white males.

Marc Mauer, assistant director of The Sentencing Project, an advocacy group that promotes alternatives to incarceration, gave a mixed review to the report.

"Increasingly, policy-makers recognize that prisons are expensive," Mauer said about the trend on the state level. He suggested that the current atmosphere of tightening budgets may have legislators rethinking sentencing to avoid building new prisons.

"The federal government is out of step with states that are finding more economical and humane ways to hold nonviolent offenders accountable for their actions," said Vincent Schiraldi, president of the Justice Policy Institute, a Washington think tank.