The geographic locations were determined using the Airport Reference Points for each airport as reported on their respective Master Records. These records were accessed using a database from the Federal Aviation Administration (FAA).

Mapping of the intersections of rail lines and our road network represented as points on a map.

The Delaware Historical Marker Program began in 1931 when the General Assembly of Delaware passed an act establishing a permanent commission to erect historical markers throughout the state. The markers in each county were numbered sequentially as they were proposed, preceded by NC (New Castle), K (Kent), and S (Sussex) to note the county in which they were located. Since the beginning of the program in the 1930s, the State of Delaware has erected more than 660 markers. The Delaware Public Archives has administered the Historical Markers Program since 1990.

Opportunity Zones are a new community development program established by Congress as a part of the Tax Cuts and Jobs Act of 2017, they are designed to encourage long-term private investments in low-income communities. This program provides a federal tax incentive for taxpayers who reinvest unrealized capital gains into "Opportunity Funds," which are specialized vehicles dedicated to investing in low-income areas called "Opportunity Zones."The zones themselves are to be comprised of low-income community census tracts and designated by governors in every state. South Carolina designated 25 percent of qualifying census tracts as an Opportunity Zone. Qualifying Zones are based on the 2011-2015 American Community Survey.