Here ya go, according to Grok: The presidential autopen has a history that dates back to the early 19th century. Thomas Jefferson was the first U.S. president to use a version of this technology in 1804, shortly after its invention in 1803 by John Isaac Hawkins. Known as a polygraph, this early device was a mechanical tool that duplicated handwriting by linking two pens—one guided by the writer and the other replicating the motion. Jefferson, an avid technophile, adopted it enthusiastically to copy his correspondence, calling it "the finest invention of the present age." He kept one at the White House and another at Monticello, using it extensively during and after his presidency (1801–1809). The modern autopen, a more automated machine capable of reproducing a pre-programmed signature without the signer’s direct involvement, emerged much later. Its commercial development began in the 1930s, with the "Robot Pen" becoming available in 1937. However, it was Robert M. De Shazo Jr. who, in 1942, created the first commercially successful autopen in response to a Navy request, marking its entry into widespread government use. In the White House, the autopen’s adoption is generally traced to the post-World War II era, with Harry Truman (1945–1953) often cited as the first president to use it regularly for routine tasks like signing letters and checks, though exact installation dates remain unclear due to limited official records. The primary reason for installing the autopen was efficiency. Presidents face an immense volume of documents requiring their signature—correspondence, military commissions, diplomatic papers, and, more recently, legislation. Manually signing each one is impractical, especially during travel or times of urgency. Jefferson’s polygraph addressed his personal need to manage correspondence, while the modern autopen was introduced to streamline administrative tasks, freeing the president to focus on governance. Its use expanded as signature demands grew with the federal government’s size and complexity, particularly after the 20th century. Presidents known to have used the autopen include: Thomas Jefferson (1801–1809): Used the polygraph, the precursor to the modern autopen, for duplicating letters.

Harry Truman (1945–1953): Believed to be the first to use the modern autopen in office, primarily for mail and minor documents.

Dwight D. Eisenhower (1953–1961): Employed it sparingly, expanding its use beyond Truman’s.

John F. Kennedy (1961–1963): Popularized the autopen, using it extensively for correspondence; his reliance was notable enough to inspire a 1965 book, The Robot That Helped to Make a President.

Lyndon B. Johnson (1963–1969): Openly embraced it, allowing photographs of the device in 1968, which led to a National Enquirer headline, "The Robot That Sits in for the President."

Gerald Ford (1974–1977): The first to publicly acknowledge its use, normalizing transparency about the practice.

Ronald Reagan (1981–1989): Used it for routine documents; once had a bill flown to China for his manual signature to avoid autopen controversy.

George H.W. Bush (1989–1993): Continued its use for correspondence.

Bill Clinton (1993–2001): Had bills flown overseas for manual signing but used the autopen for other tasks.

George W. Bush (2001–2009): Used it for routine items and sought a 2005 Justice Department opinion affirming its legality for legislation, though he never used it for bills, preferring in-person signing (e.g., rushing back from Texas for the Terri Schiavo bill).

Barack Obama (2009–2017): The first to use the autopen to sign legislation, starting with the Patriot Act extension in May 2011 while in France, followed by an appropriations bill in 2011 and the fiscal cliff bill in 2013 from Hawaii.

Donald Trump (2017–2021, 2025–present): Used it during both terms for various documents, though he’s recently criticized its use by others.

Joe Biden (2021–2025): Employed it extensively, including for executive orders and a 2024 FAA funding bill while in San Francisco; his use sparked debate in 2025 over autopen signatures on pardons.

The autopen’s evolution reflects a balance between practicality and symbolism, with its legal acceptance for legislation solidified under Obama, despite occasional constitutional debates. Its use remains a standard, if sometimes contentious, tool in the presidency.