The population of America's jails at mid-year 2014 remained steady at approximately three-quarters or a million prisoners, at 744,600 men, women, and children.  This number represents a 1.8 percent increase from 2013 levels, but still lower than the 2008 high of 785,500 persons, according to a June 2015 report from the U.S. Department of Justice's Bureau of Justice Statistics. Some 2.3 million persons languish behind bars in America when sentenced prisoners are accounted for as well, making the United States the world leader in incarceration.

Notwithstanding a widely-reported trend of decreasing crime in America, the national jail population has increased an average of 1 percent each year since 2000. More than 11 million persons were booked at American jails during the 12 month period ending June, 2014.  The national jail incarceration rate was 259 prisoners per 100,000 citizens, 302 per 100,000 when excluding juvenile populations, in a sampling survey of 942 jail facilities. There are some 2,750 jail jurisdictions across the nation.

Supporting recent statements by President Barack H. Obama and others that African-Americans are more likely suffer incarceration than other groups, blacks represented 35 percent of the total jail population at mid-year 2014 despite making up about half that percentage of the American population. Whites accounted for 47 percent of the jail numbers, and Hispanics made up 15 percent.  Notably, the female jail population has increased by 18.1 percent since 2010, while male populations have dropped 2.3 percent. 

When it comes to juveniles in jail, populations have dropped dramatically since mid-year 2000. The most recent survey found 4,200 juveniles age 17 or younger were held in jails; in 2000, that number exceeded 6,100. The percentage of juveniles in the total jail population dropped from 1.2 percent to .6 percent during the same period.  Nearly 90 percent, some 3,700 juveniles, were tried or were being held for trial in adult courts.

Specifically mentioned in the BJS report was the influx of prisoners in California's jails due to the transfer of prisoners under the California Public Safety Realignment, a response to court-mandated relief for overcrowding in the state's prisons.

Between mid-year 2011 and mid-year 2014, California's jail population grew by 13,900 prisoners. This increase required the survey's authors to assign a separate statistical weight adjustment for California, apart from the national sample. Without such a computation, "the estimated nationwide jail population would be erroneously inflated."

Source: U.S. Department of Justice, Bureau of Justice Statistics, NCJ 248629 (June 2015).