This map shows the population of individuals under 18 living in poverty across US counties in 2014, using red semi-transparent bubbles over a gray landmass with white state borders. The visualization loads TopoJSON data and renders it with `d3.geo.path` for geographic shapes, while bubble radii are scaled via `d3.scale.sqrt` based on population values. Hovering over a county triggers a tooltip displaying its name and population, and bubbles highlight with a darker stroke on mouseover. The SVG output includes static county and state paths, with the proportional bubbles layered on top.