Key Contributing

Properties containing historic resources that are listed on the National Register of Historic Places, determined to be eligible for the National Register, or resources that the consultant believes may be individually eligible for the National Register. Key Contributing resources include buildings that are community landmarks and buildings that are excellent examples of their architectural style. The four are the Paul Robeson House, the Witherspoon Street Presbyterian Church, the Witherspoon School, and Dorothea's House.

Contributing

Properties containing buildings, structures, or sites that are over 50 years of age and generally retain their integrity. Contributing buildings do not appear to be individually eligible for the National Register but contribute to the overall setting and significance of the historic district.

Noncontributing

Properties containing buildings, structures, or sites that may generally be considered to be non-historic. Two types of properties fall into this category, neither of which contribute to the historic setting or feeling of the historic district. The most obvious category of noncontributing properties are those with buildings constructed within the past 45 years, or after the "Period of Significance" for the proposed district, as recommended in this study, ends in 1969. Note: to be considered for the National Register of Historic Places (NRHP), buildings must be at least 50 years or older; Princeton's Land Use Ordinance however provides guidance for resources less than 50 years old. The second class of noncontributing buildings are those that have been enlarged or altered within the past 45 years to such an extent they no longer exhibit the historic appearance of the building.