"....Named for its primary legislative sponsor, state senator Timothy Sullivan, a notoriously corrupt Tammany Hall politician, it dates to 1911, and is still in force, making it one of the older existing gun control laws in the United States..."
The main motive for the law was to keep guns out of the hands of a rising immigrant and black population.
Now its used by the elite to keep the rif-raff from competing with their exclusive monopoly on gun ownership in New York City.