One way, not a foolproof way, is to take the closing er share stock price multiplied by the total number of outstanding shares. That gives you a rough market capitalization by date. Graph that using your favorite graphing tool.
This article originated as an answer to a question on Quora: https://www.quora.com/How-do-you-find-the-value-of-a-company-by-a-date-preferably-plotted-on-a-graphhttps://www.quora.com/How-do-you-find-the-value-of-a-company-by-a-date-preferably-plotted-on-a-graph