The most forged documents in financial history were the work of ordinary rascals who needed little skill to make money. All they needed was a camera.

Newspaper articles in the late 1850s began warning of the danger of counterfeit bank notes that had been made using photography. Both had appeared in the United States in the 1830s after President Andrew Jackson eliminated the federal banking system, allowing private banks to issue paper currency under guidelines set by each state. At one point, forgeries accounted for 40 percent of the nation’s currency, with photography often to blame.

“For a time, the ease of modification and duplication enabled by negative-positive photography seemed to be a threat rather than a benefit,” said Mazie Harris, the curator of Paper Promises: Early American Photography, a new exhibition at the J. Paul Getty Museum in Los Angeles which runs through May 27.