This is a segment of a visualization of the US' economy between 1775 and 1943. For space reasons, this segment of the graph covers back to 1901. Multiple economic measurements are included, including national debt (the red line), national income (the green line), the commodity price of goods in the US (the dashed line) and and stock values (the |-|- line that's kind of hard to see.) Multiple y-axes are scattered throughout the graph, generally around the starting point of the measurements if there is one, but all adhere to the same grid lines. It also labels certain horizontal spans with historical events that occurred in that span of time. Those labels at the very top are the US Presidents in office during that time.
This graph is a lot like the visualization of Napoleon's march, in that it correlates multiple, related points of data across a common passage of time. This makes identifying correlations quite simple. Identifying key historical events, especially wars and post-war periods, also highlights causal relationships between world events and economic performance. We can also observe patterns emerging over time, in effect proving that history does tend to repeat. The main drawback of this visualization it its tendency to be rather busy in certain areas. In addition to the crossing of multiple lines of varying visibility, actually measuring the magnitude of any given measurement against its axis requires some knowledge about which axis should be used. Similarly, many of the labels and notations on the visual require some understanding of the historical occurrences and dynamics of their economic area. For instance, one segment of the visual highlights an area of commodity prices between 1841 and 1847 with arrows and notes "Wholesale commodity prices 1910-14-100". To the average user, the meaning of this annotation won't be immediately obvious.
Seeing the economic trends of the last 16 or so decades was generally interesting to me. However, two points immediately stuck out to me when viewing it. First, national income was fairly steady, climbing annually at rarely changing rates, until about 1916. After that, it quickly shot up, then began rollercoastering around until the end of the visual. The second thing was how completely the lack of business activity during the Great Depression eclipsed both the prosperity that preceded it, and any other depression that had come before it. Worse, during that period, everything except the federal debt (stock prices, commodity prices, income) followed. It's a stark depiction of how monumental the Great Depression was.