Mapping Then and Now

When the Corps of Discovery set out in 1804, the territory was uncharted. Part of their mission was to observe and record information so that accurate maps could be made.

Lewis and Clark used a variety of scientific instruments to calculate locations, sketch maps of their progress, and study the plants and animals they encountered. Determining the team's latitude and longitude, an important and difficult task, required several tools.

• Determining Location in 1803–1806
• Mapping Tools in 1803–1806
• Learn More About Mapping in 1803–1806

Determining latitude and longitude is simpler today thanks to far more sophisticated tools. Modern technology can now tell you the features of the ground you stand on within a few inches.

• Determining Location in 2006
• Mapping Tools in 2006
• Learn More About Mapping in 2006

St. Louis then. Mapping was a manual process in 1803–1806, producing hand-drawn or laboriously printed maps.

St. Louis now. GIS technology produces maps that can show multiple layers of information at once, creating "smart" maps.