States, counties, cities and organizations all erect historical markers and designate landmarks. Exploring them leads to a greater understanding of local history.
State Historical Markers, Landmarks and Registers
Each state and United States territory has a State Office of Historic Preservation (SHPO) which is charged with the identification and listing of historic properties. The SHPOs can nominate properties to the National Register of Historic Places but can also set up state-wide registers to recognize historic places at the state level. This process is known as designating landmarks.
Some states also run a system of state historic sites, typically historic buildings and sites owned and operated by the state.
Some state historical registers equip their designated landmarks with plaques or markers. Others do not. The most common scenario is that only some of the state landmarks have plaques, usually either because property owners don’t want to draw attention to their homes or because they simply don’t want to pay for a marker.
Other offices compile inventories, comprehensive surveys of historical resources for the state. However, while registers confer a legal status on the site, inclusion in a survey or inventory does not.
State Historical Marker Programs
SHPOs also sometimes set up state historical marker programs, separate from their historic registers, but such programs are equally likely to be run by state historical societies or other preservation organizations. Standalone marker programs do not necessarily confer any kind of protection on a site, but they do draw attention to the historic resource and encourage tourism.
There seems to be a tradition among official marker programs that the marker should take a particular style with a raised, rounded top. Very few historical marker programs completely diverge from this style (one example would be Idaho, which has large-format rectangular signs).
Certified Local Governments and the Creation of Local Historic Landmarks and Markers
Certified local governments, or CLGs, are cities and counties which work with the National Park Service, through the SHPO, to set up plans for the preservation of local areas, most often towns and cities.
Becoming a CLG implis that the preservation plan has met the criteria to receive certain grants and become part of various National Park System programs. A lack of certification does not prevent a city from setting up its own official landmarks or marker program, and indeed many do.
Historical Markers from Organizations
Several organizations, including the American Society of Civil Engineers, have their own landmark systems in which where they recognize sites of particular importance to their field. These systems are more likely than not to have plaques.
Other Kinds of Historical Markers
Any organization in the USA may set up historical markers and plaques as long as they receive the correct permissions. Organizations such as E Clampus Vitus and the Daughters of the American Revolution are particularly prolific. Such plaques may or may not have an agenda, be historically accurate, or follow any kind of cohesive system.
The same, of course, can be said for older historical markers; preservation organizations have in recent years started to rework their systems and reevaluate purple prose, inflammatory language and, according to author James W. Loewen in his book Lies Across America, blatant untruths.