Upon gaining statehood, West Virginia adopted the law of Virginia. Both the 1863 and the 1872 constitutions (especially the latter) were patterned after Virginia's Constitution of 1851, although the new state added important provisions guaranteeing equal apportionment, equal taxation, and public education.

Early issues arose out of the Civil War's after effects. "Test oaths—oaths swearing that the taker had never engaged in rebellion against the United States—were used to bar ex-Confederates from, among other things, voting, filing lawsuits, and holding public office. The state Supreme Court upheld each oath that it considered. Resentment against the oaths and hostility to the government were intense. A federal court ruling in 1870 and the 1871 Flick Amendment to the state constitution restored voting rights for the ex- Confederates. They and their sympathizers then took control of West Virginia, and the following year saw a new constitution proposed and ratified. Although the 1872 Constitution eliminated the Northern-style local government system and re-adopted the local government model that had prevailed in Virginia before the war, it otherwise did not differ that much from its 1863 predecessor. It remains in effect today, much amended.

The remainder of the 19th century was a period of relative stability in West Virginia law. No constitutional changes of real significance occurred. Attention focused on the Supreme Court of Appeals in the aftermath of the extremely close gubernatorial election of 1888. Doubt about the count's integrity led the legislature to forgo declaring a winner when it met the following January. On inauguration day, both major party candidates, the president of the senate (as the successor in case of a vacancy), and the incumbent governor, claimed the executive office. Ruling in Goff v. Wilson and Carr v. Wilson, the Supreme Court agreed with the incumbent governor that he should remain in office until his successor was certified and sworn in. The legislature met the following January and finally certified the winner of the election.

No doubt the 1888 election, which was riddled with vote fraud, provided much of the impetus for the electoral reforms that soon followed, including the adoption of the "Australian" or standardized printed ballot in 1891. The effect was to give West Virginia voters, for the first time, a realistic opportunity to cast a secret ballot. A constitutional amendment of 1901 required voter registration in 1902.

The decades immediately before and after the turn of the century saw legal developments reflecting the strains of converting from an agrarian to an industrial society and the emergence of the extractive industries, timber, coal, oil, and gas. Much litigation was devoted to disputes over land titles, mineral and timber rights, workers' injuries, and labor disputes. A new era of social insurance began with the passage of the state's first workers' compensation law in 1913. So long as the employer paid his premiums into a state-run fund, or guaranteed self insurance, injured workers could not sue but would be entitled to compensation without regard to who was at fault in the accident.

The 1932 Tax Limitation Amendment brought major changes to the state's tax and finance system, imposing stringent limits on the rates at which property could be taxed. The immediate effect was near chaos, as local governments suddenly found themselves without the means to deliver basic services. The Supreme Court nevertheless enforced the amendment against legislative efforts to allow local governments to circumvent the limits. The long-term effects have been to force local governments to adopt a variety of other revenue-raising strategies, and, most importantly, to shift primary responsibility for funding public education away from local property taxes and onto the state treasury.

Throughout their first century, West Virginia's law-making bodies were, for the most part, conservative institutions, often dominated by coal interests and having little interest in governmental or social change. The 1960s, however, introduced a reform era that persisted long enough to accomplish meaningful change. In 1968, the legislature proposed, and the people adopted, the Modern Budget Amendment, which streamlined and detailed the budget process while significantly increasing the governor's budgetary role and power. Two 1970 amendments allowed governors to succeed themselves and established a commission of private citizens to deal with legislative pay. The Judicial Reorganization Amendment of 1974 restructured the court system, enhanced the Supreme Court's powers to administer the system, and substituted a more equitable magistrate court system for the old justice of the peace courts. In 1982, responding quickly to a Supreme Court decision, the legislature proposed a constitutional amendment that equalized and modernized the procedures for property tax assessments across the state. The people ratified it that same year.

The 1960s and 1970s also saw the passage of various statutes reforming government and expanding governmental regulation over private industrial and commercial activity. The legislature enacted, for example, laws giving citizens a right to notice about and to attend most government meetings, creating a citizen's right of access to most governmental documents, and imposing ethical requirements on public officials and employees. Other laws passed during the reform period promoted environmental protection, mine safety, consumer protection, and equal treatment in the workplace and in public accommodations.

The trend toward reform and activism had a longer run in the Supreme Court than in the political branches. Beginning in the 1960s, accelerating in the 1970s, and continuing into the 1990s, decisions from the Court expanded judicial protection of individual rights, modernized tort law, rewrote governmental immunities doctrines, caused a major overhaul of the property tax system, and mandated reforms in major governmental institutions. The Court required state officials and the legislature to overhaul (among other things) the juvenile justice system, the mental health system, the prison system, and the school finance system.

Through the years, Supreme Court decisions reshaped West Virginia law in important ways. A trilogy of heavily criticized cases State ex rel. Nance v. Mays, Ex parte Jones, and Hatfield v. Graham-was decided during a 1913 labor rebellion and accorded vast power to the executive branch to use martial law and to preempt civilian courts. A later ruling, Ex parte Lavinder (1921), only moderately tempered that power. West Virginia-Pittsburgh Coal Company v. Strong (1947) significantly limited surface mining; it established that deeds severing and conveying mineral rights did not authorize the owner of the minerals to use methods of extraction that were more disruptive to the surface owner's rights than methods in use at the time of conveyance. In a case of both legal and political importance, State ex rel. Smith v. Gore (1964) required equal apportionment in the election of delegates to a constitutional convention and derailed a move to draft a new state constitution. Pauley v. Kelly (1979) recognized the fundamental right of every child in West Virginia to an equal and effective education and led to the so-called Recht Decision calling for a restructuring of the state's school finance system. Pittsburgh Elevator Company v. West Virginia Board of Regents (1983) permitted (in effect) the legislature to waive the state's sovereign immunity. Proclaiming the state's commitment to equality, Allen v. West Virginia Human Rights Commission (1984) ordered the Commission and other state officials to ensure prompt consideration of human rights complaints. Another long-standing civil action, Crain v. Bordenkircher (1986—95) ultimately resulted in a finding that the conditions at the state penitentiary failed to meet constitutional standards and led to the construction of a new facility. Many cases, recently including State ex rel. Barker v. Manchin (1980), Frymier-Halloran v. Paige (1996), and West Virginia Citizens Action Group v. West Virginia Economic Development Grants Committee (2003), have set forth basic principles governing separation of powers among the branches of government.

Many individuals have been instrumental in shaping the law in West Virginia. The two Supreme Court justices with the longest tenures on the court, Frank Haymond (1945-72) and Henry Brannon (1889-1912), both exerted a persuasive force on their colleagues, as did George Poffenbarger (1901-22). Three recent justices enjoyed both a long tenure and widespread respect for their work. Richard Neely (1973-95) wrote with an eloquent and erudite flair in both his opinions and in substantial off-the-court books and articles. The opinions of Thomas Miller (1977-94) were known for their careful research and craftsmanship and those of Thomas McHugh for their solid reasoning. Two justices from the 1970s, Charles H. Haden Jr. (1972-75) and James Sprouse (1973-75), performed admirably on the court and went on to give distinguished service on the federal bench, Haden as a district judge and Sprouse with the court of appeals. Haden was the only Republican since 1928 to have won election to the Supreme Court. In 1988, the voters elected Margaret Workman, the first woman to sit on the high court. She remained there with high marks for her work until resigning in 1999. In 2008, she was elected to another term on the court, retiring at the end of 2020.

Franklin D. Cleckley has contributed in multiple ways. As a lawyer, he gained fame as a highly skilled trial and appellate advocate in civil rights cases from 1970 through the 1990s. His treatises on criminal procedure and evidence have dominated those fields in the state since their publication, and as a professor at the state's law school he has exerted a profound influence on many members of the bar. In 1994, he became the state's first Black justice on the Supreme Court, where he served until 1996. During that time, he wrote many scholarly opinions that left a legal legacy far exceeding the brevity of his tenure. Another individual who has achieved prominence at various levels is Arthur Recht, who was highly regarded as a lawyer and then as a trial judge. In the latter role, he was assigned and decided critical aspects in cases involving the constitutionality of the West Virginia school finance system and its penitentiary. He served with distinction on the Supreme Court from 1994 to 1996.

The work of attorney Dan Hedges did much to shape the reforms of the 1970s and 1980s. Working primarily as a lawyer for legal services programs, Hedges won major cases across a spectrum of issues that included public education, welfare, juvenile justice, consumer law, mine safety, the environment, civil rights, mental health institutions and procedures, and prisoners' rights.

In 1878, the 11-year-old West Virginia University created a "chair of law and equity," thus establishing what would become the College of Law. Throughout its existence, it has been West Virginia's only law school, and most of the state's lawyers have graduated from it.

To practice law in West Virginia, a lawyer must gain admission to and maintain membership in the West Virginia State Bar, which is an administrative agency of the Supreme Court. Discipline and regulation of lawyers are administered through the Office of Disciplinary Counsel, another agency of the Supreme Court.

Various private groups with a legal focus have also formed. The oldest is the West Virginia Bar Association, whose membership has primarily comprised attorneys representing business and commercial interests. The West Virginia Trial Lawyers Association focuses on the concerns and interests of lawyers representing plaintiffs in tort litigation, divorce clients, and criminal defendants. The Mountain State Bar Association, organized 1915, deals with issues particular to racial and ethnic minorities. Other lawyer groups have formed around various practice specialties.