Despite his preference for unpredictability, we know exactly what President Trump will be discussing on June 14: The American flag. The occasion? A day dedicated to the Stars and Stripes.
If you're caught unawares, don't get wrinkled. Flag Day comes up short in the holiday hierarchy. It's that "runty stepchild among American national holidays," according to the New York Times.
We don't get off work, after all.
Flag Day poster produced by the Pennsylvania branch of the Federal Arts Project, an initiative of the Works Progress Administration, ca. 1933. From the Works Projects Administration posters collection [V99]
But the observance gives us a moment to consider the story of the flag itself, what it means today, and how this has developed throughout our history.
First, some background. The American flag has changed in tandem with the country. We are currently flying the 27th official version, last updated in 1960 with the admission of Hawaii's star.
We see it so much that the flag has perhaps become part of the scenery. We tend not to give it much thought once school's out and we aren't daily pledging our allegiance to it.
Photograph depicting students and their teacher looking on as John Wintersteen, Jr. raises the American flag in front of William Penn Charter School (Penn Charter) ca. 1941. From the Philadelphia Record photograph morgue [V07]
But we remain sensitive about Old Glory and flags in general. Flag burning may be protected speech, but the act rouses animal spirits in many. And consider the continuing controversy over the Confederacy's standard.
But what is it that we're looking at? Myth threads through the story of the American flag. Let's stitch together some facts.
Why red, white, and blue? Your correspondent asked several Philadelphia natives what the colors signified. A consensus could not be reached save for red. They were certain it represented the spilt blood of patriots.
"Three cheers for the red, white and blue." From the Civil War Envelope Collection 
This is where things get tricky. The federal government does not in fact maintain an official opinion on the matter. Go figure.
We traditionally defer to the reasons cited for selecting that chroma trio in the Great Seal of the United States: "White signifies purity and innocence. Red hardiness and valour and Blue ... signifies vigilance, perseverance, and justice."
From the entire color spectrum, why did our continental counterparts choose these three? A quick gander at the U.K.'s Union Jack offers a clue. Past is prologue.
When it comes to who made the first flag, the seams separating fact from fiction really start to stretch.
The story of George Washington tasking a local upholsterer, Betsy Ross, with the job is likely just that: a story. It first appeared after the Civil War with an address delivered at the Historical Society by William Canby, Ross' grandson.
"This lady is the one to whom belongs the honor of having made with her own hands the first flag," bellowed Canby in the historic library.
Well, the sole evidence supporting his claim are affidavits of Ross' descendants. You be the judge - they are available for research here at 1300 Locust St.
If the Continental Congress was not explicit about the significance of the flag's colors, they were particular about its structure. On June 14, 1777, the delegates "Resolved, that the flag of the 13 United States shall be 13 stripes, alternate red and white; that the Union be 13 stars, white on a blue field, representing a new constellation."
We'd be forgiven for thinking the flag's status as a national symbol of unity and patriotism is traced to the American Revolution. But as with the Liberty Bell, we'd be wrong.
During the War of Independence, "flag makers . . . thought of themselves as suppliers of military goods," observed historian Marla Miller.
The prominence of the flag itself is more intimately tied to the Civil War.
The idea of Flag Day emerged during the conflict, proposed by a New England newspaperman. Northern titans of textile manufacturing were equally enthusiastic - printing innovations allowed for flags to be mass produced for the first time.
Photograph depicting President Abraham Lincoln raising the flag in front of the State House (Independence Hall) ca. 1861. From the Historical Society of Pennsylvania print collection [V89]
Of the flag's primacy, consider that Congress began conferring the Medal of Honor in 1862. That first year it awarded 1,500-plus. More than half pertained to flag-related acts of gallantry. By this they referred to either rescuing the flag from falling into the hands of the Confederate Army or capturing the rebel standard.
President Woodrow Wilson proclaimed June 14 as Flag Day on the eve of the First World War, another time of disunity. Under Harry Truman, Congress made it official. Pennsylvania celebrates the occasion as a state holiday.
First World War-era poster created by the United States Food Administration urging Americans to "Beat Germany" by eating less food and wasting nothing to "support every flag that opposes Prussianism." From the Historical Society of Pennsylvania war posters collection [V95]
Here in Philadelphia, Flag Day has been celebrated the city over.
"12,000 students of six public high, junior, and elementary schools vowed their faithfulness to the American flag at Benjamin Franklin High School," ran the 1943 headline of the Philadelphia Record, a now-shuttered daily.
The Record also witnessed a more private ceremony for the city's residents. "Dario Lombardelli, 733 Carpenter St., a native of Italy, is shown presenting the Stars and Stripes to Miss Ann Virgil, teacher of a WPA sponsored citizenship class conducted at the Neighborhood Center, 428 Bainbridge St. . . . The other member of the group of 30 soon-to-be citizens is Irvin Ornstein, from Germany."
Honoring the flag does not mean we must suspend our critical faculties. For every heroic hoisting on Iwo Jima there is a shameful lowering in the desert internment camps for Japanese Americans. The flag, like us, is complicated and contradictory.
"I am what you make me; nothing more," remarked Secretary of the Interior Franklin Lane in 1914. "I swing before your eyes as a bright gleam of color, a symbol of yourself."
This article originally appeared in the June 11, 2017 Philadelphia Inquirer as part of HSP's weekly series, Memory Stream.