Concealed carry, or carrying a concealed weapon (CCW), is the practice of carrying a weapon (such as a handgun) in public in a concealed manner, either on one's person or in close proximity. CCW is often practiced as a means of self-defense. Every state in the United States allows for concealed carry of a handgun either permitless or with a permit, although the difficulty in obtaining a permit varies per jurisdiction. There is conflicting evidence regarding the effect that concealed carry has on crime rates. A 2023 review by the RAND Corporation concluded there is supportive evidence that shall-issue concealed carry laws are associated with increased firearm homicides and total homicides. Earlier studies by RAND found that shall-issue concealed carry laws may increase violent crime overall, while there was inconclusive evidence for the effect of shall-issue laws on all individual types of violent crime. A 2004 literature review by the National Academy of Sciences concluded that there is no link between the existence of laws that allow concealed carry and crime rates. History The Second Amendment to the United States Constitution guarantees the right to "keep and bear arms". Concealed weapons bans were passed in Kentucky and Louisiana in 1813. (In those days open carry of weapons for self-defense was considered acceptable; concealed carry was denounced as the practice of criminals.) By 1859, Indiana, Tennessee, Virginia, Alabama, and Ohio had followed suit. By the end of the nineteenth century, similar laws were passed in places such as Texas, Florida, and Oklahoma, which protected some gun rights in their state constitutions. Before the mid-1900s, most U.S. states had passed concealed carry laws rather than banning weapons completely. Until the late 1990s, many Southern states were either "No-Issue" or "Restrictive May-Issue". Since then, these states have largely enacted "Shall-Issue" licensing laws, with numerous states legalizing "Unrestricted concealed carry" and the remaining "May-issue" licensing laws being abolished in 2022 by the U.S. Supreme Court. State laws Permitting policies Unrestricted jurisdiction: one in which a permit is not required to carry a concealed handgun. Most states in this category allow any non-prohibited person to carry regardless of state of residency, with the sole exception of North Dakota. Permit requirement jursdiction: one in which a permit is required to carry a concealed handgun. Historically, some states were considered "may-issue" jurisdictions where an applicant was required to provide a proper cause or need to be issued