 Matsell's efforts would soon influence police reforms which would not only be adopted in New York with the passage of the Municipal Police Act in 1844, but throughout the United States as well.Under the act, police departments were given a larger responsibility over the city and New York Mayor William Frederick Havemeyer would soon promote Matsell as police chief of the newly created New York City Police Department.Among the new reforms under Matsell's administration, patrol methods were improved and a strict discipline instilled, the results of which would be seen during the Astor Place Riots of 1849 and common violence seen during between Nativist and Tammany supporters during New York's political elections.