From Mar ‘18 Forbes article, Quote:
Here’s the background. After the Civil War, most members of Congress were concerned that if the states had a free hand, they and their officials would often violate the civil rights of freed slaves and other unpopular groups. So Congress passed and President Grant signed the Civil Rights Act of 1871, which included this provision language (now known as 42 U.S. Code Section 1983):
“Every person who, under color of any statute, ordinance, regulation, custom, or usage, of any State or Territory, of the District of Columbia, subjects or causes to be subjected, any citizen of the United States or any other person within the jurisdiction thereof to the deprivation of any rights, privileges, or immunities secured by the Constitution and laws, shall be liable to the party injured in an action at law, suit, or equity, or other proper proceeding for redress.”
Thus, individuals whose rights were violated by police or other officials could sue them in federal court. It was supposed to deter bad actors who violate the rights of people in the course of their duties. The law says nothing whatsoever about those officials having any defenses against those suits.
Nevertheless, the Supreme Court invented a defense known as “qualified immunity. unquote.
Also from the same article, an interesting downloadable discussion ‘thesis’ on the subject can be found here: https://chicagounbound.uchicago.edu/public_law_and_legal_theory/620/
Fourth sentence of the document, quote: Does it insulate officials too much from liability, leaving them without adequate incentives to respect the constitutional rights of those they encounter? unquote.