Passing generations have not eroded Atchison’s pride in Ms. Earhart. The aviator’s face is embedded in the city logo, and the Amelia Earhart Memorial Bridge crosses the Missouri River leading into town. Also bearing her name: Atchison’s airport, a local highway and a museum at her birthplace on North Terrace Street.

Ms. Earhart grew up during Atchison’s heyday, but subsequent decades brought floods, a drop in population and, more recently, the beginnings of a downtown revival.

Lewis and Clark camped on these hills during their westward expedition, and the city that sprouted later served as a hub along the Atchison, Topeka & Santa Fe Railway. Today, the steep, brick-paved residential streets remain lined with stately homes dating to Atchison’s glory years, though some have fallen into disrepair. This city has also been home to a Rock & Roll Hall of Fame member, three Kansas governors and a United States senator, but most everyone agrees that Ms. Earhart is the most notable export.

“She’s quite our headliner,” said David Butler, a nearly lifelong Atchison resident who said that the newest claims about the flier’s disappearance had dominated conversation at his coffee club. Mr. Butler said he was personally curious to know what happened to Ms. Earhart, but also thought Atchison benefited from all the theories.

“I think the uncertainty is probably better for us in keeping her memory alive,” Mr. Butler said.

Over the weekend, festival participants, many fresh with questions after watching the new documentary, signed a birthday card for Ms. Earhart, toured the white house overlooking the river where she spent much of her youth and visited Trinity Episcopal Church, where the font used in Ms. Earhart’s baptism is still at the front of the sanctuary. The weekend later took a tragic turn: On Sunday, a stunt pilot who had performed at the festival and an employee of the Atchison airport died in a plane crash.

On Saturday, residents spoke with pride as they told tourists that Ms. Earhart was more than just a record-setting pilot, but also a social worker, writer and a feminist decades ahead of her time. At the Earhart Birthplace Museum, volunteers recited details about the aviator’s former home — the wallpaper is nearly identical to when she lived there, and the woodwork untouched — and pointed to a collection of books offering disparate conclusions about her fate.