What U.S. Patent Number is officially cited for Morgan's traffic control signal system?

Answer

U.S. Patent No. 1,475,024

The official documentation cited shows that Morgan was granted U.S. Patent No. 1,475,024 for his traffic control signal system.

What U.S. Patent Number is officially cited for Morgan's traffic control signal system?
inventioninventorAutomobiletraffic lighttraffic control