Sounds like a fun data exercise, but let me break it down. First, you need a clear key: each sprint milestone gets a specific hue, and each historical event gets its own. Then, align the dates on a single axis, maybe a Gantt style, so the 1868 fire’s peak is in the middle of your chart. If you want to go deeper, calculate the lag between the fire’s peak and each milestone, then see if there’s a pattern in how your team’s velocity shifts relative to that. Just remember to keep the colors distinct enough that the chart doesn’t become a rainbow blur. If you can tidy that up, you’ll have a neat visual that’s both analytical and a little historic.