2020 Census Tracts; PA, NJ, DE & MD

*USE geoid TO JOIN DATA DOWNLOADED FROM DATA.CENSUS.GOV* The TIGER/Line Shapefiles are extracts of selected geographic and cartographic information from the Census Bureau's Master Address File (MAF)/Topologically Integrated Geographic Encoding and Referencing (TIGER) System (MTS). The TIGER/Line Shapefiles contain a standard geographic identifier (GEOID) for each entity that links to the GEOID in the data from censuses and surveys. The TIGER/Line Shapefiles do not include demographic data from surveys and censuses (e.g., Decennial Census, Economic Census, American Community Survey, and the Population Estimates Program). Other, non-census, data often have this standard geographic identifier as well. Data from many of the Census Bureau’s surveys and censuses, including the geographic codes needed to join to the TIGER/Line Shapefiles, are available at the Census Bureau’s public data dissemination website (https://data.census.gov/). Census Tracts are small, relatively permanent statistical subdivisions of a county or statistically equivalent entity that can be updated by local participants prior to each decennial census as part of the Census Bureau’s Participant Statistical Areas Program (PSAP). The Census Bureau delineates census tracts in situations where no local participant responded or where state, local, or tribal governments declined to participate. The primary purpose of census tracts is to provide a stable set of geographic units for the presentation of statistical data. Census tracts generally have a population size between 1,200 and 8,000 people, with an optimum size of 4,000 people. A census tract usually covers a contiguous area; however, the spatial size of census tracts varies widely depending on the density of settlement. Census tract boundaries are delineated with the intention of being maintained over a long time so that statistical comparisons can be made from census to census. Census tracts occasionally are split due to population growth or merged as a result of substantial population decline. Census tract boundaries generally follow visible and identifiable features. They may follow nonvisible legal boundaries, such as minor civil division (MCD) or incorporated place boundaries in some states and situations, to allow for census tract-to-governmental unit relationships where the governmental boundaries tend to remain unchanged between censuses. State and county boundaries always are census tract boundaries in the standard census geographic hierarchy. Tribal census tracts are a unique geographic entity defined within federally recognized American Indian reservations and off-reservation trust lands and can cross state and county boundaries. The tribal census tracts may be completely different from the standard county-based census tracts defined for the same area. (see “Tribal Census Tract”). Downloaded from https://www2.census.gov/geo/tiger/TIGER2022/TRACT/ on June 22, 2023**使用地理标识符（GEOID）关联从data.census.gov下载的数据集** TIGER/线形状文件（TIGER/Line Shapefiles）是从美国人口普查局主地址文件（Master Address File, MAF）/拓扑集成地理编码与参考系统（Topologically Integrated Geographic Encoding and Referencing System, MTS）中提取的精选地理与制图信息集合。此类文件为每个实体配备标准地理标识符（GEOID），可与人口普查及调查数据中的GEOID建立关联。TIGER/线形状文件本身不包含普查与调查的人口统计数据，例如十年一次人口普查、经济普查、美国社区调查以及人口估计项目的相关数据。其他非普查来源的数据集通常也带有该标准地理标识符。美国人口普查局的多项普查与调查数据（包括可用于关联TIGER/线形状文件的地理编码字段）均可在该局公开数据发布网站（https://data.census.gov/）获取。 普查区（Census Tracts）是县或统计等效单元的小型、相对固定的统计分区，可由本地参与者在每十年一次人口普查前，作为人口普查局参与者统计区域项目（Participant Statistical Areas Program, PSAP）的一部分进行更新。当无本地参与者响应，或州、地方或部落政府拒绝参与时，由人口普查局划定普查区。普查区的核心用途是提供一套稳定的地理单元，用于统计数据的可视化呈现。普查区的人口规模通常介于1200至8000人之间，最优规模为4000人。普查区一般覆盖连片区域，但其空间范围因定居密度差异而存在显著区别。普查区边界的划定原则为长期保持稳定，以便在不同次人口普查之间开展统计对比。普查区偶尔会因人口增长而拆分，或因人口大幅减少而合并。 普查区边界通常遵循可见且可识别的地物；在部分州及特定场景下，也可遵循不可见的法定边界，例如小民政分区（Minor Civil Division, MCD）或已设建制地方的边界，以实现普查区与行政单元的对应关系——这类行政边界在两次人口普查之间通常保持不变。在标准普查地理层级体系中，州界与县界始终作为普查区边界。部落普查区是在联邦认可的美洲印第安人保留地及保留地外信托土地内划定的独特地理单元，可跨越州界与县界，其划定方式与基于县的标准普查区完全不同（详见“部落普查区”条目）。 本数据集于2023年6月22日从https://www2.census.gov/geo/tiger/TIGER2022/TRACT/ 下载获取。