Now, 10 months later, despite May extending Queen Elizabeth II's offer of a state visit to the UK -- the pomp and pageantry of which would no doubt delight Trump -- he has not taken up the offer.
There is a chill on the "special relationship." Indeed, the 45th President is having a significant cooling effect on most of America's international relationships.
Returning this week to Washington for Thanksgiving -- my wife is American and one of my daughters studies here -- the nation's capital feels as though it pushes more than it pulls -- keeping the world and its leaders at arm's length.
One former career public servant told me that the Trump White House is undermining the country's global standing as a power for good.
According to several DC insiders I've met, cutbacks and firings are leaving many feeling they are fighting the good fight of American interests overseas with one hand tied behind their back, led by a boss who is out of his depth.
The day I arrived State Department spokeswoman Heather Nauert addressed this very issue, saying
, "It breaks my heart to hear some feel they aren't needed or aren't wanted or aren't appreciated"
As many as 60%
of US career ambassadors have quit this year. One former US ambassador, Barbara Stephenson, is quoted as saying
: "Our leadership ranks are being depleted at a dizzying speed," accusing Trump of decapitating the State Department.
Wendy Sherman, a former undersecretary of state for political affairs and a principle architect of the Obama-era Iran nuclear deal, is scathing in her condemnation of Trump. "Quite frankly, this administration is categorically destroying the Department of State and devaluing diplomacy as something important in this world."
For many veterans of US diplomacy, Washington has come adrift of its moorings.
In recent months, the pace of big-name leaders touching down there has slackened. Early-season visits by Xi Jinping, Shinzo Abe, Angela Merkel and Justin Trudeau have passed.
May is not the only international leader to have discovered President Trump is in fact Candidate Trump and that he heads an America in retreat. No longer is America seen by all as the unshakable standard bearer for free trade and democracy.
One of the first international umbilical cords on Trump's chopping block was US membership in Trans-Pacific Partnership
-- the 12-nation agreement that not only sought a multinational trade pact but did so to make stronger diplomatic partners of the member nations in that region to push back against China's growing influence.
Trump's impulse to read the TPP as simply a trade deal disadvantaging America blew up in his face on his recent Asia tour. While he was still in Vietnam attending the Asia-Pacific Economic Cooperation summit, his host -- along with Japan's Abe -- signed the TPP deal without Trump and America.
America's influence is thereby diminished.
It was a diplomatic slapdown coming just one day after Trump told the Vietnamese, Abe and the other APEC leaders that the United States was open for bilateral trade deals. Trump's "America First" policy came in second that day.
The open arms of DC diplomacy are gone. A rather more barbed "America First" glowers from the ramparts of the White House -- and the capital's residents are living this.
From driver to teacher to researcher to student to journalist to civil servant, many I talked to feel ill at ease with the effects of that America First policy so far.
And Trump's agitation of the status quo comes at a bad time.
The post-World War II order that has been steady for several generations is getting wobbly: China's expansion, Russia's invasions and meddling, Iran and Saudi locking horns, rising populist nationalism.
Right now the world needs a rock, and Trump's America offers anything but. Indeed, where most of the world is aligned on global warming, Trump is not.
"Yes," one Washington insider told me, the universe does still revolve around DC. But it does so now in bigger and bigger orbits, father and farther away.
From tiny acorns mighty oaks grow, and DC embodies all of that. On the steps of the Lincoln Memorial above the Reflecting Pool, Martin Luther King Jr.'s immortal words have a resting place chiseled into the stone: "I have a dream."
A few steps away, above Lincoln's huge statue, passively powerful in his armchair repose, the words carved in the wall above him speak of the love of his citizens for his unifying if troubled leadership:
"In this temple, as in the hearts of the people for whom he saved the Union, the memory of Abraham Lincoln is enshrined forever."
If ever there were a message that today feels like it belongs to a bygone era, this is it. Because for all their eloquence, these are only words carved in stone, not set in it. Today they seem to lack permanence.
They are not commandments to which Trump is tethering his presidency.
An analogy doing the rounds in Washington that a former career public servant drew my attention to hints at the depth of anger, frustration and division. Presidential historian Robert Dallek was quoted as saying
: "A fish rots from the head downwards ... and the stench of this administration starts at the very top."
To this outsider arriving after almost a year's absence, such language is a shocking indictment of the erosion of civility in political discourse. It is exactly the attitude that will upset Trump and many Republicans but reveals just how bitter recriminations are set to become.
Washington's worldly ties are being severed. The State Department not only has a hiring freeze but is short-staffed and lacks the hands to answer all the calls coming its way.
One European told me he has taken to having journalists to dinner in the hopes they can enlighten him as to what is going on.
But it's not just diplomats who notice how DC's international buzz is ebbing. It's the everyday people in tough everyday jobs whose hard graft keeps the capital ticking who are also noticing the change.
Trump's domestic policies on undocumented migrants have teachers wondering which of the Dreamers won't show up for class next week. At universities, students on the verge of graduating and giving back what society has given them are now kept awake by worries of deportation to countries they no longer know.
His failure to see white supremacists for what they are and apparent ability to see Muslims for what they are not, coupled with poorly conceived travel bans, play badly in Washington's melting-pot society.
Even a short cab ride with someone from a migrant family quickly becomes a conversation about the damage they fear Trump is doing to society.
Many left homes halfway round the world to raise families here. And they chose to come because they wanted to be part of the American dream.
Washington feels less international because of Trump's rhetoric and policies.
Overseas embassies here, the diplomatic lifeblood of DC, aren't shuttering their doors just yet. But they are battening down the hatches, hoping better days will come.