The Yonkers police force was formed in response to the influx of "transients" flooding the streets after the American Civil War. Newspapers described the existing town constables as "ineffective" and at a special town meeting a resolution was passed to hire fourteen Metropolitan officers from New York City to serve the community. These NYC police officers started in Yonkers on August 10, 1866, forming a substation of the New York 32nd Precinct.

By April 10, 1871, John T. Hoffman, the governor of New York signed an act that formed Yonkers' own local police force which consisted of one captain, two sergeants, two roundsmen, 18 patrolmen, 1 hostler and one doorman. The Captain of Police position was given to John Mangin who served as a sergeant in the original New York City Policemen stationed in Yonkers. The annual salary for a patrolman in Yonkers in 1871 was $750. Any man who was interested in becoming a Yonkers Policeman had to go through an interview with the Board of Commissioners and pass a medical examination by a police surgeon. No written examination was required. The appointment was for life, contingent on good behavior.

During the 1870's, the Yonkers Police Department had two sub-stations. The first sub-station was located in Kingsbridge, south of Yonkers. And the second location was in Bronxville. Patrolling of the town was carried out by foot patrol, mounted patrol and horse and wagon patrol. The mounted patrols were primarily used in the remote areas of Yonkers. Every policeman had two shifts; his first tour duty and his reserve duty. At the completion of his first shift, a policeman is required to remain at the station for an additional 8 hours. Beds were provided at the headquarters for sleeping. This requirement was to ensure that there was a sufficient amount of personnel should an emergency occur.