Richard Grimmett wrote a history of St. John’s Church on Lafayette Square. The Episcopal church is known as the “church of the presidents.” (John Kelly/The Washington Post)

Richard "Dick" Grimmett is the sort of person docents hate.

Oh, most docents are decent, but when showing visitors around a historic property, they sometimes let a good yarn get in the way of actual history. Dick is an actual historian, and he cannot countenance such laxity. To him, apocrypha are anathema.

Dick chairs the properties committee at St. John's Church, the fetching little place of Episcopal worship on Lafayette Square that is celebrating its bicentennial. The cornerstone was laid on Sept. 14, 1815, and it hosted its first worship service on Oct. 27, 1816. It's famous as the "church of the presidents," its prime location drawing residents of the White House for nearly as long as there's been a White House.

Isn’t it right that every president has attended a service at St. John’s?

Not exactly, Dick said. "Every person who has held the office of president has attended at least one service at St. John's, since Madison."

It’s an important distinction, and one that Dick was careful to make in his 350-page history of St. John’s, which was published in 2009.

Dick is careful in his pronouncements. A retired international security specialist for the Congressional Research Service with a PhD in American diplomatic history, he thought writing the book would entail simply cobbling together highlights from earlier histories. But he was skeptical about some of the tales that had become church lore.

Take the church's bell, for example. Everyone knew that it was a gift from James Monroe, made by Paul Revere's son out of a melted British cannon captured during the War of 1812.

“I said, ‘Hey, did anybody ever read the contract?’ ” Dick remembered. He found it in the church’s archives in a folder marked “Miscellaneous.” (Dick said all historians know that folders marked “Miscellaneous” hold the best stuff.)

“We’ve got the correspondence where the guy says, ‘Well, Mr. Revere has a bell that weighs so much and is toned on the note A. We have another bell that’s in the process of being built. Do you want to wait for it or take this one?’ ”

St. John’s took the bell off the rack. Not made from a cannon.

And not paid for by Monroe. Rather, St. John’s followed the lead of a church across town. In 1822, the Unitarian church that became All Souls convinced the District’s commissioner of public buildings that since it was located near the city’s post office and other important buildings, a bell there would be a useful alarm in case of a fire. The city chipped in some money to pay for it.

A year later, St. John’s made the same argument. After all, it was close to where the president lived. Monroe authorized $100 to help pay for the bell.

"The docents were furious with me," Dick said of his general debunking. "I'm tearing down all their good stories. But that's a better story."

Though I'd walked past St. John's countless times, before last week I'd never been inside. Dick showed me around the handsome building. Its original Greek-cross design was created by Benjamin Latrobe, the U.S. Capitol's first architect. (Latrobe was also the church's first organist.)

Since Franklin D. Roosevelt's time, St. John's has offered itself to incoming presidents for a pre-inauguration prayer service. And since James Madison's time it has been visited by the powerful. Some of those visitors were not quite so powerful when they visited as they would become later, which accounts for Dick's careful language: visited by every person who has held the office of president, since Madison.

Take James Garfield, for example. Garfield didn't visit St. John's in the six months he was president before his assassination. But Dick found that when Garfield was an Ohio congressman, he had attended the wedding of Treasury Secretary Salmon Chase's daughter at St. John's in 1863.

Herbert Hoover was even harder to nail down. But Dick dug until he discovered that in 1925, when Hoover was a member of Calvin Coolidge's Cabinet, he went to St. John's for the funeral of Gen. Nelson Miles.

In the depths of the Civil War, Abraham Lincoln would sometimes walk to St. John's from the White House and settle into a pew at the back. Those visits earned the church a role in Steven Spielberg's 2012 movie.

"I'm on the soundtrack," said Hayden Bryan, executive director of operations at St. John's.

A sound technician had Hayden ease the so-called Lincoln pew back and forth to record its squeak. “It makes kind of a bullfrog sound,” Hayden said.

Spielberg laid that noise into a scene where Lincoln rocks in a rocking chair. Other scenes include the creak of Hayden walking across the church’s wooden floor in his penny loafers. And the St. John’s bell rings out at the movie’s climax, as the 13th Amendment, abolishing slavery, is passed.

“Spielberg wanted to fill the movie with sounds Lincoln would have heard,” Dick said.

Go to St. John’s and you can hear them, too.

Twitter: @johnkelly

St. John's, 1525 H St. NW, is open to visitors 9 a.m. to 3 p.m. Monday through Saturday. There are tours Sundays at about 12:15 p.m. stjohns-dc.org.

For previous columns, visit washingtonpost.com/johnkelly.