Qualified immunity has become one of the Supreme Court's most controversial doctrines. But while there has been plenty of commentary criticizing the Court's existing clearly-established-law test, there has been no thorough historical analysis examining the complicated subject of state-officer immunities under nineteenth-century common law. Yet the legitimacy of state-officer immunities, under the Court's precedents, depends on the common law as it existed when Congress passed the Civil Rights Act of 1871. In the Supreme Court's own words, it cannot "make a freewheeling policy choice" and must apply immunities that Congress implicitly adopted from the "common-law tradition." This Article therefore provides the first comprehensive review of the common law on state-officer immunities around 1871. In particular, it canvasses the four nineteenth-century treatises that the Supreme Court consults in assessing officer immunities under the common law of 1871: Cooley's 1879 Law of Torts-, Bishop's 1889 Commentaries on Non-contract Law; Mechem's 1890 Law of Public Offices and Officers; and Throop's 1892 Law Relating to Public Officers. Not only do these treatises collect many overlooked state common law precedents, but they rely heavily on the Supreme Court's own, often ignored, nineteenth-century decisions. These historical sources refute the prevailing view among modern commentators about one critical aspect of qualified immunity. This Article confirms that the common law around 1871 did recognize a freestanding qualified immunity protecting all government officers' discretionary duties--like qualified immunity today. But many other important features of the Supreme Court's current officer-immunity doctrines diverge significantly from the common law around 1871: (1) High-ranking executive officers had absolute immunity at common law, while today they have only qualified immunity; (2) qualified immunity at common law could be overridden by showing an officer's subjective improper purpose, while today a plaintiff must satisfy the stringent clearly-established-law test; and (3) the plaintiff had the burden to prove improper purpose with clear evidence, while today there is confusion over this burden. Restoring the common law around 1871 on state-officer immunities could address many modern problems with qualified immunity, and these three features from the common law provide a roadmap for reforming the doctrine. If high-ranking executive officials have absolute immunity, that would sufficiently protect the separation of powers without resort to the clearly-established-law test--which frequently denies plaintiffs money damages when their constitutional rights are violated by lower-ranking executive officials. At the same time, if plaintiffs in qualified immunity cases have the burden to prove lower-ranking officers' subjective bad faith with clear and convincing evidence, then officer defendants and courts will have significant procedural mechanisms to dismiss insubstantial claims before trial.