For Flag Day, watch how much the American flag has changed

In 1916, Flag Day was established by national proclamation in order to commemorate the anniversary of the adoption of a flag by the Second Continental Congress in 1777. The relatively recent establishment of the holiday makes sense. Before then, the American flag was in a constant state of flux.

Specifically, before 1912 states could put almost whatever they wanted in the canton of the flag. (The canton is what vexillologists — people who study flags — call a separate quarter in a flag. It's the blue rectangle in the American flag.) But in 1912 there was a huge change: the US officially adopted the 48-state flag.

Because these flags represent, in a way, the entire history of the United States, there's a lot to tease out. (You can pore over the flag source list here — it includes some, but not all, major American flag designs.)

Here are some key points:

• Early flags were chaotic because of the absence of a national template. From 1777 to 1795, all of these flags and more were in use to represent the same exact number of states:

Phil Edwards/Vox

The flag from 1777 to 1795.

• The flag's change was rapid as the US brought new states into the fold. Take, for example, 1845 to 1855. In that decade, there were at least eight different flag designs in use.

Phil Edwards/Vox

Flags from 1845 to 1855. (Phil Edwards/Vox)

• From 1912 to 1959, there was an at-the-time unprecedented period of stability both for the country and the flag, with no new states added:

Phil Edwards/Vox

The flag from 1912 to 1959.

• The flag we have today is the longest-lasting flag in American history. With the additions of Hawaii and Alaska in 1959, and the current flag issued by 1960, the United States — both in flag and state makeup — is more stable than it's ever been:

Phil Edwards/Vox

The flag from 1960 to present.

So what's the best way to celebrate Flag Day? The United States' flag has been more versatile than we might assume — in a way, it's a hybrid of a political symbol and, thanks to its ever-changing canton, a good old-fashioned chart.

But in President Woodrow Wilson's original proclamation for Flag Day in 1916, he offered some loftier guidance for the unique holiday:

It has therefore seemed to me fitting that I should call your attention to the approach of the anniversary of the day upon which the flag of the United States was adopted by the Congress as the emblem of the Union, and to suggest to you that it should this year and in the years to come be given special significance as a day of renewal and reminder, a day upon which we should direct our minds with a special desire of renewal to thoughts of the ideals and principles of which we have sought to make our great Government the embodiment.