Debtors probably accounted for about 90% of prisoners in England in 1670. Based on fragmentary available evidence, the number of imprisoned debtors peaked at roughly 15,000 in 1670. John Howard’s prison inspections about 1780 found that debtors accounted for about 50% of prisoners, and non-debtors numbered about 2,000 prisoners. Imprisonment of non-debtors consisted primarily of persons awaiting trial. Criminal punishments were typically not imprisonment, but rather corporal punishment, transportation, or death. The number of non-debtor prisoners in 1670 was probably similar to the number in 1780, adjusted for the growth in the total population of England. That implies a debtor share of about 90% of prisoners in 1670. While that figure is subjected to considerable uncertainty, that the debtor share in 1670 was much higher than the 50% debtor share about 1780 is beyond reasonable doubt.
The magnitude of imprisonment for debt declined greatly over time. The share of debtors among prisoners fell from about 90% in 1670 to about 10% in 1840. In 1838, Parliament limited imprisonment for debt to cases in superior courts. The Debtors Act of 1869 formally abolished imprisonment for debt. That statute criminalized fraudulent acts of debtors and established a sentence of up to six weeks of imprisonment for contempt of court for debtors who could pay, but did not. From 1869 to 1914, about 6700 debtors per year were imprisoned on less than six-week terms.^ Civil imprisonment, including imprisonment for debt, was abolished in the United Kingdom in 1970.