JOHNSBURG, N.Y. — Everyone in town, including the police, is asking why. And the answer to that is unknown, since they are also asking another question — who?

For nearly a year, the theft of a commemorative marker has baffled the police and wounded this Adirondack town’s civic pride. The sign was located near the birthplace of Mathew B. Brady, a pioneering photojournalist whose images brought the horrors of Civil War battlefields to the public.

Brady’s portraits of Abraham Lincoln have adorned the $5 bill, and Lincoln credited pictures that Brady took of him during the 1860 campaign with helping him become president by making his likeness familiar to voters throughout the country.

“It’s incomprehensible to me that whoever, for whatever reason, would do this,” said Delbert Chambers, the president of the Johnsburg Historical Society.