At a museum on Fifth Avenue in New York City, in a sparkling reception hall overlooking Central Park, Jamie Dimon convened his top executives and their spouses last month for the Wall Street equivalent of a pep rally.

“I’m proud of the company,” Dimon, the chief executive of JPMorgan Chase, said at the event, held at the Museum of the City of New York. According to people who attended, Dimon said. The next week, Dimon aimed to put one of his bank’s woes behind him.

On Sept. 24, hours before the Justice Department was planning a news conference to announce civil charges against the bank over its sale of troubled mortgage investments, Dimon called one of Attorney General Eric Holder’s top lieutenants to reopen settlement talks, people briefed on the talks said. The rare outreach from a Wall Street CEO scuttled the news conference and set in motion negotiations that have culminated in a tentative $13 billion deal, according to the people briefed on the talks.

An account of the negotiationspulls back a curtain on the private wrangling to illuminate how the bank and the government managed to negotiate what would be a record deal.

Much of the deal came down to dollars and cents. Dimon traveled to the Justice Department in Washington for a meeting with Holder that underscored how expensive the healing process had become. At the meeting, people briefed on the talks said, Dimon raised made an offer of $11 billion.

But Holder wanted more to resolve civil cases, the people briefed on talks said. And he refused to provide JPMorgan a so-called nonprosecution agreement that would halt an investigation from prosecutors in California.

While they were unable to strike a deal that day, late Friday, the pair reached a tentative deal: $13 billion and no promise of dropping criminal investigation.