When Hillary Clinton delivered the news to Tim Kaine that he was her pick for running mate, the senator from Virginia was in Rhode Island doing that most prosaic of political work: raising money for his colleague Jack Reed at the Newport Shipyard.

The call came through at 7:32 p.m. Friday. Clinton offered the job, Kaine accepted and then the former secretary of state said: “Now, I don’t want to alarm you, but John Podesta is outside your building right now.”

So it was that a process begun in secret more than three months ago — which had remained a mystery throughout, even to those who were being vetted — came to its cloak-and-dagger conclusion.

“It’s certainly something quite different from the usual course of affairs, particularly for someone going through it for the first time. It’s this odd, in-between world — being talked about a lot, but really the process goes on within the privacy of the campaign,” said Housing Secretary Julián Castro, who was under consideration.

“It was a very well done, very professionally done process. I give the campaign tremendous credit for the discipline and how thorough they were,” Castro added.

Watch the highlights of presumptive Democratic presidential nominee Hillary Clinton and Sen. Tim Kaine in their first joint appearance as running mates at a campaign rally in Miami on July 23. (Claritza Jimenez/The Washington Post)

Clinton had started with an initial list of close to 30 names, said an aide who spoke on the condition of anonymity to discuss internal deliberations candidly. Each was given an initial vet, the results of which were delivered to her Chappaqua, N.Y., home by Podesta, the campaign chairman, shortly after the April 19 New York primary.

Podesta and longtime Clinton confidante Cheryl Mills had compiled them in binders, which the campaign chairman stashed in oversize plastic bags from Duane Reade, the ubiquitous New York drugstore chain.

Although the list was long, Kaine’s name had always been presumed to be near the top, both among those involved in the process and in the frenzied public speculation. “There was a rhythm to this,” said one person familiar with the process who also spoke on the condition of anonymity. “It’s like a race where there are three, four or five horses moving up and moving back. Kaine was always there. . . . I think there was a presumption all along.”

The winnowing began with the vetting materials being distributed to teams of lawyers from different firms. Candidates were encouraged to make frequent television and campaign appearances, with Clinton’s team watching to see how well they came off in making the case for her candidacy.

Finalists were summoned to meet privately with Clinton, starting with Kaine, 58, who had his first serious conversation with her about the vice presidency on Thursday, July 14.

“Why don’t you come back to the house later?” she asked him after they appeared together at a rally in Annandale, Va.

The meeting at her home on Whitehaven Street — within walking distance of where Kaine will live, if she is elected — lasted an hour and a half. Podesta sat in on the beginning of it, then left them to themselves.

That did not become public, but a procession of other people would be spotted by the media going in and out of her house over the following days.

Kaine, however, would be the only candidate called back for a second meeting with the nominee-in-waiting.

That one took place over lunch at her house in Chappaqua on Saturday, July 16. Kaine brought his wife, and Clinton was joined by former president Bill Clinton, daughter Chelsea and son-in-law Marc Mezvinsky.

A decision without chaos

Once she settled on him early in the week, there would be no wavering, none of the public drama that marked the chaotic final hours before Donald Trump formally announced his pick, Indiana Gov. Mike Pence.

In Clinton’s case, operational security would be maintained right up to the end. A speech was written, and a plan was hatched. Those who did not get the nod were notified of that, either by Clinton or Podesta, before she dialed Kaine.

Podesta and three aides known as the “go team” had slipped out of her Brooklyn headquarters Friday afternoon, taking the freight elevator to avoid the reporters staking out the front of the building.

Once they made contact with Kaine in Newport, they whisked the senator and his wife, Anne Holton, back to their hotel to grab their things and headed for Miami, where they would land at 2 a.m.

Aboard the flight, Kaine worked on a draft that had been written for him by speechwriter Megan Rooney, and he became better acquainted with Matt Paul, who had been Clinton’s Iowa state director and will now be part of Kaine’s travel team.

Podesta’s chief of staff, Sara Latham, who had managed the vetting process for him , coaxed the senator to pull out his harmonica. Which he did, and he played them a Beatles song. Kaine also called President Obama, whom he had supported over Clinton early in the bitter 2008 Democratic presidential primary and on whose shortlist he had been for vice president eight years ago.

According to a person familiar with the weekend’s schedule, the campaign did not tell staff workers on the ground who would be announced at the events Friday in Tampa or Saturday in Miami — or whether someone would be announced at all. The events were planned to accommodate a number of possible running mates.

Personal chemistry is a hard thing to force, in politics just as in life. But it seemed to be there when Clinton and Kaine made their first appearance Saturday in Miami as the Democrats’ ticket for the fall.

Kaine was not the name on her list who had the longest and deepest relationship with Clinton, who is famous for valuing those traits. That would have been Agriculture Secretary Tom Vilsack, who has known her since the 1970s. She was instrumental in helping him win a tough race for Iowa governor in 1998, and they have been there for each other in the trenches ever since.

Nor was affable, mild-mannered Kaine the pick who would have brought the most pizzazz to the ballot.

That might have been Sen. Elizabeth Warren (D-Mass.), the darling of the liberal left; or the charismatic Sen. Cory Booker (D-N.J.); or Castro or Labor Secretary Tom Perez, both Hispanics whose selection would have given the first woman to lead a major party ticket a double-down claim on making history.

And, yes, Kaine does represent a crucial swing state, but using a vice-presidential selection to pick up favorite-son electoral votes is a gambit that has not worked since New Englander John F. Kennedy named Lyndon B. Johnson of Texas in 1960.

Clinton, having seen the White House from the inside, knows that what she has made is a kind of marriage proposal, one she may have to live with for as many as the next eight years.

Or as Podesta, himself a former White House chief of staff, told her last Monday: “It needs to be someone who, whenever they walk into a room, you are glad to see them, and you want them as part of any conversation.”

And, of course, someone who will be an asset in what promises to be a brutal fall campaign.

Clinton had been impressed by a number of the candidates. An aide said she had particularly enjoyed events with Booker and Perez.

Warren did not expect to be picked for at least two reasons: A Republican governor in Massachusetts would be able to appoint a Republican to replace her; and a ticket with two women was widely seen as a bridge too far. Nonetheless, Warren and Clinton have developed a good relationship after a number of conversations, not all of them vice president-related, over the past weeks.

A common thread

Kaine, for his part, had caught Clinton’s eye during the drawn-out Democratic primary against Sen. Bernie Sanders of Vermont. He made frequent appearances on her behalf, making a “very polite” argument that she was the candidate better prepared on foreign policy, a Clinton aide said.

In that first private meeting with Kaine about the job, the Clinton official added, the two talked about how they had both spent time while getting their Ivy League law degrees doing work for the disadvantaged — she giving outlet to her Methodist values working for the Children’s Defense Fund, and he with the Jesuit Volunteer Corps in Honduras.

“She saw a common thread in the role that faith played in guiding both of their entries into public service,” the aide said.

Some of the other contenders offered their congratulations to Clinton’s pick. “KAINE IS ABLE!!!” Booker tweeted shortly after word got out.

And just having been in contention has the effect of elevating the stature of those who were talked about — as Kaine could attest from having been in contention for the job that eventually went to Vice President Biden.

“In life, the road turns, and you don’t know how things are going to work out, and that often times, things can work out for the better, so I’m looking forward to the years ahead,” Castro said.

Back in 2008, Tim Kaine might have been thinking the very same thing.

Anne Gearan, Ed O’Keefe, Abby D. Phillip in Miami and John Wagner in Richmond contributed to this report.