This interactive visualization maps the U.S. daily cigarette smoking rate from 1996 to 2012 across counties, showing changes over time through a choropleth map with a slider. A tooltip displays each county’s 1996 and 2012 rates along with the change. The visualization uses D3 v4’s `d3.geo` module with the Albers USA projection, `d3.nest` for data organization, and `d3.scale.threshold` for color coding, rendering SVG paths for counties and states. Data comes from the Institute for Health Metrics and Evaluation.