Joseph Cosey: The Forger Who Fooled Collectors with “Lincoln” Letters

Joseph Cosey forged letters by Abraham Lincoln and others for decades. Some of his forgeries still circulate in collections today, now openly labeled as his work.
Articles by Bart Baggett.
Articles by Bart Baggett.

Joseph Cosey forged letters by Abraham Lincoln and others for decades. Some of his forgeries still circulate in collections today, now openly labeled as his work.

Mark Hofmann’s forged Mormon documents fooled collectors, the church, and even federal investigators—until document examiners uncovered the truth. This case ended in tragedy and changed how experts approach questioned documents.

In 1983, sixty volumes of supposed Hitler diaries fooled historians and publishers—until forensic testing revealed modern paper and ink. The case is a lesson in why originals matter.

Sherwood Morrill, California's lead document examiner, compared the Zodiac letters to the main suspect's writing—and ruled him out. Sometimes, exclusion is the answer that matters most.

In 1971, Clifford Irving convinced a major publisher that he had Howard Hughes’s authorized autobiography—using forged documents. Here’s how the deception unfolded, and why even respected experts can be misled without genuine writing to compare.

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