The Sullivan Act is a gun control law in New York state that took effect in 1911. The NY state law required licenses for New Yorkers to possess firearms small enough to be concealed. Private possession of such firearms without a license was a misdemeanor, and carrying them in public was a felony.

Sullivan introduced the state-wide legislation “partly in response to a marked increase in highly publicized violent street crime below Fourteenth Street.”^[2] Sullivan and other prominent New Yorkers were under public pressure to act, in the form of letters and recommendations from George Petit le Brun, who worked in the city’s coroner’s office, after a “brazen early afternoon” murder-suicide near Gramercy Park. The law went into effect on August 31, 1911.^[3]

The law also made it a felony to own or sell other items defined as dangerous weapons, including “blackjacks, bludgeons, sandbags, sandclubs, billies, slungshots and metal knuckles.”^[4]

According to Richard F. Welch, who wrote a 2009 biography of Sullivan, “all the available evidence indicates that Tim’s fight to bring firearms under control sprang from heartfelt conviction.”^[5] At the time, “some complained that the law would only succeed in disarming lawful citizens, while others suspected that Sullivan was just trying to rein in the thugs on his own payroll.”^[6] Lawman Bat Masterson, a friend of Sullivan’s, criticized the law as “obnoxious” and said that he questioned Sullivan’s mental state of mind over the law.

Source: wiki