Friday is the last day of work for more than 200 people at the New Era plant in Derby.
The sports apparel company announced plans to close the facility back in November, a move New Era said was to keep pace with competitors moving away from owning and operating manufacturing plants.
That news was met by protests from union leaders, elected officials and even the MLB Players Association.
New Era made a deal with the Communications Workers of America, the union representing the plant's employees, to provide severance benefits for workers affected by the closure.
Critics said the shutdown will have a devastating effect on the small hamlet of Derby.
New Era's company headquarters are located in downtown Buffalo.