Skip to main content
100%

HOLC 1939

✓ Published0🌍 Public
Aandyrutkowski
Last edited Oct 11, 2018
Created on Oct 11, 2018

This interactive map uses Mapbox GL JS to display two historical raster maps of Los Angeles from 1939, overlaid on a modern basemap. Two sliders control the opacity of the HOLC and Watts map layers, while clicking on either layer reveals popups with property type and name from the Greenbook. The map also includes point layers from the 1939 and 1947 Greenbook, rendered with Mapbox’s queryRenderedFeatures API. The code builds the visualization with blockbuilder.org and relies on Mapbox-hosted raster sources.

AI-generated description

Built with blockbuilder.org

mit Licensed

Similar vizzes

Loading thumbnail…

HOLC 1939

An interactive Mapbox GL map displays two overlaid raster layers of Home Owners' Loan Corporation (HOLC) maps from 1939, centered on Los Angeles and Watts. Two sliders control the opacity of each raster layer, allowing side-by-side comparison of the historical redlining districts. Clicking on the map reveals popups with the district type and name from the GeoJSON layers. The map uses Mapbox GL JS v0.44.1 with custom raster sources and built-in popup functionality.

Aandyrutkowski
93% match
Loading thumbnail…

DLF Project Map

This interactive map overlays two historical raster layers—HOLC 1939 redlining maps and Watts 1965—on a Mapbox GL base map centered on Los Angeles. Two range sliders control the opacity of each layer independently, allowing visual comparison of neighborhood classifications and later urban conditions. A clickable Green Book layer displays point features with popups showing property type and name. The visualization uses the Mapbox GL JS API with raster sources and setPaintProperty for opacity adjustments.

Aandyrutkowski
82% match
Loading thumbnail…

Show and hide layers

This interactive map displays two historical layers of Los Angeles: redlining boundaries from 1939 and locations from the same year’s Green Book. A menu of toggleable layer names lets users show or hide each raster or vector source independently. Built with Mapbox GL JS v0.44.1, the code adds both layers on map load and uses `map.getLayoutProperty` and `map.setLayoutProperty` to switch visibility. The raster HOLC layer and the circle-styled Green Book points come from Mapbox-hosted tilesets.

Aandyrutkowski
81% match
Loading thumbnail…

DLF Project Map

This interactive map overlays two historical raster layers—a 1939 HOLC map and a 1965 Watts map—on a Mapbox GL base map, with sliders controlling each layer’s opacity. A third layer from the 1947 Green Book displays point features; clicking a point opens a popup with its name and type. Built with Mapbox GL JS, the map uses raster sources from Mapbox tilesets and queryRenderedFeatures for interactivity.

Aandyrutkowski
77% match
Loading thumbnail…

Display a map

A map centered on Los Angeles displays a raster layer with an adjustable opacity slider. The example uses the Mapbox GL JS library to render the map and the `map.setPaintProperty` method with `raster-opacity` to control layer transparency. A slider input updates the opacity value, while a click event on the map triggers a popup showing the name and type of a feature from a layer called `47greenbook-dapl9g`. The map style and raster source come from Mapbox-hosted data.

Aandyrutkowski
73% match
Loading thumbnail…

Show and hide layers

This example uses Mapbox GL JS to display a map of Los Angeles with two overlay layers: a Watts curfew map and a 1939 HOLC redlining map. A menu in the top-right corner contains toggle links for each layer. Clicking a link toggles the layer’s visibility via `map.getLayoutProperty` and `map.setLayoutProperty`, updating the active class on the link. Both layers are raster sources loaded from Mapbox tiles, rendered on top of a custom map style.

Aandyrutkowski
73% match
Loading thumbnail…

Display buildings in 3D

This example displays buildings in 3D on a Mapbox GL map centered on downtown Los Angeles, with a tilted and rotated perspective. It uses the Mapbox GL JS API to render a `fill-extrusion` layer from the `building` source-layer in the `composite` vector source, which contains OpenStreetMap building-height data. The extrusion height and base are interpolated from zoom level 15 to 15.05, creating a smooth transition as the user zooms in, with a gray color and 0.6 opacity.

AAlan McConchie
66% match
Loading thumbnail…

Los Angeles Heat Islands and Covid

This visualization displays a world map with country boundaries, rendered using SVG and a Natural Earth projection. It highlights the geographic context for a study of Los Angeles heat islands and Covid, though the map itself focuses on global landmasses and graticule lines. The code uses d3.geoPath and d3.geoNaturalEarth1 for projection and path generation, with topojson to parse world-atlas data for country features and interior boundaries. Styling is applied via CSS classes, with landmasses filled in teal and graticules in light gray.

MMatthew Talty Colvard
64% match