US jails held, as confined inmates, 621,149 people in 2000; 767,434 people in 2009; 748,728 people in 2010; 735,601 people in 2011; 744,524 people in 2012; 731,208 people in 2013; 744,592 people in 2014; 727,400 people in 2015; and 740,700 people in 2016.
The above are mid-year counts of inmates confined by local jails on the last weekday of June for each year. Counts were estimated from the Annual Survey of Jails.

There were 704,500 people confined in local jails in the US on December 31, 2016, of whom 602,200 were male and 102,300 were female. Juveniles held as adults numbered 3,000, plus an additional 700 juveniles who were held as juveniles. Racial demographics were as follows: white, 338,700; black/African-American, 242,200; Latinx, 107,200; American Indian/Alaska native: 8,600; Asian/native Hawaiian/other Pacific islander: 5,600; two or more races: 2,100.

On December 31, 2015, state and federal prisons combined held a total of 1,476,847 people, of whom 499,400 were non-Latinx whites, 523,000 were non-Latinx blacks, 319,400 Latinx, and 135,100 whose race/ethnicity was counted as "other".

Click here for complete datatable of Number of People in the US Serving Time in State and Federal Prisons, by age, sex, race, and Latinx ethnicity, on December 31, 2015

"The spectacular growth in the American penal system over the last three decades was concentrated in a small segment of the population, among young minority men with very low levels of education. By the early 2000s, prison time was a common life event for this group, and today more than two-thirds of African American male dropouts are expected to serve time in state or federal prison.

"Of the 2.3 million inmates in custody, 2.1 million were men and 208,300 were women (table 9). Black males represented the largest percentage (35.4%) of inmates held in custody, followed by white males (32.9%) and Hispanic males (17.9%).

"Over a third (33.8%) of the total male custody population was ages 20 to 29 (appendix table 10). The largest percentage of black (35.5%) and Hispanic (39.9%) males held in custody were ages 20 to 29. White males ages 35 to 44 accounted for the largest percentage (30.1%) of the white male custody population.

"There were 431 prisoners sentenced to more than one year in state or federal prison per 100,000 U.S. residents at year-end 2018, a decrease from 441 per 100,000 at year-end 2017 (table 5). The state imprisonment rate was 381 sentenced prisoners per 100,000 U.S. residents of all ages, and the federal rate was 50 per 100,000.

"The custody incarceration rate for black males was 4,618 per 100,000. Hispanic males were incarcerated at a rate of 1,747 per 100,000. Compared to the estimated numbers of black, white, and Hispanic males in the U.S. resident population, black males (6 times) and Hispanic males (a little more than 2 times) were more likely to be held in custody than white males. At midyear 2007 the estimated incarceration rate of white males was 773 per 100,000.