Robert Spring was indeed a 19th century forger, known for his skill in forging and selling letters allegedly written by famous historical figures. Here are some key points about him:

1. Born in England in 1813, Spring later immigrated to the United States.

2. He began his forgery career in the 1850s, specializing in creating and selling letters purportedly written by George Washington, Benjamin Franklin, Thomas Jefferson, and other American historical figures.

3. Spring's forgeries were of high quality and fooled many collectors and historians of the time.

4. He operated primarily in Philadelphia and New York City.

5. In 1860, Spring published an autobiography titled "The American Autograph Fake," in which he confessed to his crimes.

6. After serving time for his forgery activities, he moved to Canada around 1865.

7. Spring died in 1891 in Toronto, Canada.

8. His forgeries had a lasting impact on the study of American history and autographs, leading to increased scrutiny and authentication methods for historical documents.

Spring's story is often cited as an example of how forgers can have a significant impact on historical research and collecting, even long after their activities have ceased.