In 1982, seven citizens living in the area generally served by Co.7, met and decided to begin the formal process of establishing a volunteer organization committed to serving the Citizens of Calvert County. The Board of Calvert County Commissioners voted to support the construction and equipping of a new station in St. Leonard in 1984. The ground was broken in June of 1986. The station was declared "in service" on the 8th of March, 1987. In 1987, Co. "7" with only one engine and one ambulance ran 438 calls.

Since 1987, Co. "7" has grown and currently houses (2) PL Custom Ambulances, (2) Pierce Engines, Tanker 7, Heavy Duty Rescue Squad 7, Mass Casualty Unit 7, Jeep 7, BX 7, Brush 7, Car 7, Utility 7, and Command 7.

For the calendar year 1997, the sixty-five (65) volunteer members responded to 1,845 medical, rescue and fire emergencies. The volunteers devoted 4,621 hours to training, 12,657 hours to operations and 846 hours to general duties and fund raising, for a total of 25,738 hours.

At the Sate Firemen's Convention held annually, the Zembower Memorial Training Award for having the most amount of training in the state was awarded to Co. "7" for the 1989, '90 and '91 calendar years. Co, "7" was the first and only department in the history of the Zembower Memorial Training Award to get this most prestigious award three years consecutively.

For the calendar year 2004, the 118 volunteer members responded to 1,564 medical, rescue, and fire emergencies. The volunteers devoted 5,061 hours to training, 5,486 hours to fundraising, and 15,714 hours to general duties. The department also received funding for a new rescue boat as well as purchased to property adjacent to the firehouse. At the 2005 Maryland State Fireman's Association Convention, St. Leonard once again took home the Zembower Memorial Training Award for having the most amount of training that year per member in the state.