Number of People in Jails in the US

"County and city jails in the United States held 738,400 inmates at midyear 2018 (table 1), a decline of 6% from 785,500 inmates held in 2008. Te midyear population remained relatively stable from 2011 to 2018.

"At midyear 2018, about one-third of jail inmates (248,500) were sentenced or awaiting sentencing on a conviction, while about two-thirds (490,000) were awaiting court action on a current charge or were held for other reasons.

"Over the 10-year period from 2008 to 2018, the rate of incarceration in local jails dropped by 12%, from 258 inmates per 100,000 U.S. residents to 226 per 100,000 (fgure 1). During this period, the jail incarceration rate increased by 12% for whites and declined by about 30% for blacks (28%) and Hispanics (33%)."

Source: 

Zhen Zeng, PhD. Jail Inmates In 2018. Washington, DC: US Dept. of Justice Bureau of Justice Statistics, March 2020. NCJ253044.