Growth of Jails in the US 2000-2016
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.
On December 31, 2015, jails in the US held 692,500 confined inmates, and on December 31, 2016, jails in the US held 704,500 confined inmates. The Bureau of Justice Statistics warns against comparison of mid-year and end-of-year inmate counts "because the jail population goes through seasonal change, typically with fewer inmates at year-end than at midyear."