United States Army Combat Capabilities Development Command

Aberdeen Proving Ground (APG) (sometimes erroneously called Aberdeen Proving Grounds) is a U.S. Army facility located adjacent to Aberdeen, Harford County, Maryland, United States. More than 7,500 civilians and 5,000 military personnel work at APG. There are 11 major commands among the tenant units, including: United States Army Communications-Electronics Command (CECOM) United States Army Combat Capabilities Development Command (CCDC) United States Army Test and Evaluation Command (ATEC) Edgewood Arsenal Adelphi Laboratory Center The Army Reserve Information Operations Command Unified Cross Domain Services Management Office HQ, U.S. Army Contracting Command (Army Contracting Command –APG, Adelphi Contracting Division) U.S Army 93rd Signal Network - Network Enterprise Center Logistics Readiness Center U.S. Army Cyber Operation Group – 335th Signal Command Blossom Point Research Facility

United States Army Materiel Systems Analysis Activity (AMSAA) is an analysis organization of the United States Army. AMSAA's overall goal is to provide soldiers with the best U.S. Army materiel possible. AMSAA supports the U.S. Army by conducting systems and engineering analyses to support decisions on technology, materiel acquisitions, and the designing, developing and sustaining of U.S. Army weapon systems.

The Ballistic Research Laboratory (BRL) was a leading U.S. Army research establishment situated at Aberdeen Proving Ground, Maryland that specialized in ballistics (interior, exterior, and terminal) as well as vulnerability and lethality analysis. BRL served as a major Army center for research and development in technologies related to weapon phenomena, armor, electronic devices, and high-speed computing. In 1992, BRL was disestablished and its mission, personnel, and facilities were incorporated into the newly created Army Research Laboratory (ARL).BRL is perhaps best known for commissioning the creation of ENIAC, the first electronic general-purpose digital computer.

Poplar Hill is a historic home located at Aberdeen, Harford County, Maryland. It is a 1+1⁄2-story, gambrel-roofed frame house, built in the mid-18th century. A late-19th-century one-bay, two-story, gable-roofed wing is attached.Poplar Hill was listed on the National Register of Historic Places in 1976.

Aberdeen station is a train station in Aberdeen, Maryland, on the Northeast Corridor. It is served by Amtrak Northeast Regional intercity service and MARC Penn Line commuter service. The station has two side platforms serving the outer tracks of the three-track Northeast Corridor, with a station building on the north side of the tracks.

The Havre De Grace Police Department (HDGPD) is a full-service agency servicing the incorporated municipality of Havre De Grace, Maryland. Established in 1981, HDGPD is Havre De Grace's primary law enforcement agency.

The Aberdeen Police Department (APD) is the primary police agency servicing a population of 14,130 within 6.4 square miles (17 km2) of the municipality of Aberdeen, Maryland.

Aberdeen is a city located in Harford County, Maryland, United States, 26 miles (42 km) northeast of Baltimore. The population was 16,254 at the 2020 United States Census. Aberdeen is the largest municipality in Harford County. Aberdeen is part of the Baltimore-Towson Metropolitan Statistical Area (MSA), which is the 20th-largest United States metropolitan area. The nearest city to Aberdeen is Havre de Grace, 4.8 miles (7.7 km) to the northeast.

Aberdeen station is a former Baltimore and Ohio Railroad (B&O) station in Aberdeen, Maryland. The station was designed by architect Frank Furness, who designed some 40 stations for the B&O in Delaware, Maryland, and Pennsylvania. The station has deteriorated in condition mightily since B&O ended service in 1955, and was almost torn down in 2003. An eleventh hour agreement was made by CSX and the Historical Society of Harford County to save the building. The station was transferred from the Historical Society of Harford County to the Aberdeen Historical Museum in 2016.

Swansbury is a historic home and complex located at Aberdeen, Harford County, Maryland, United States. The buildings are clustered together near the center of the 86.78-acre (351,200 m2) forested property. The complex consists of a five-bay, two-story, multi-part, frame residence and several period frame dependencies. The oldest part of the house dates to about 1760, with major Federal style additions made in the late 18th or every early 19th century. Also on the property are an array of eleven frame outbuildings (barns, wash house, poultry houses, meathouse, etc.) which seem to date from the early 19th century. The grounds are dotted with ancient exotic specimen trees and shrubs.Swansbury was listed on the National Register of Historic Places in 1994.

James B. Baker House is a historic home located at Aberdeen, Harford County, Maryland. It is a large three story frame residence constructed in 1896 in the Queen Anne style. It features multiple gables, projections, dormers, and balconies enlivening its essentially square form and high hipped roof. James B. Baker was a leading entrepreneur in the canning industry.It was listed on the National Register of Historic Places in 1982.

Aberdeen High School is a public high school in Aberdeen, Maryland, United States. It is a part of the Harford County Public Schools.