The disappearance of Charley Ross was the first kidnapping case for ransom in the United States. Four-year-old Charley and his older brother, six-year-old Walter, were kidnapped on July 1, 1874. Charley never returned. 

For many days leading up to their kidnapping, two men in a horse-drawn buggy visited the brother's Philadelphia neighborhood, offering them candy, according to the Library of Congress. 

On July 1, 1894, the men offered to buy Charley and Walter candy and fireworks ahead of the upcoming 4th of July holiday. They were successful in luring the boys into the buggy. 

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Walter was sent into a store to buy fireworks. While he was inside, the men drove off with Charley. 

Walter was later returned home by a stranger, according to USHistory.org, but Charley was still missing. 

Several days after Charley was taken by kidnappers, his father, Christian Ross, received the first of 23 ransom letters from his son's abductors, according to the Library of Congress. 

One of the letters read, "Mr. Ros: be not uneasy you son Charley Bruster, be all writ we got him and no powers on earth can deliver out of our hand," according to the Pennsylvania Center for the Book.

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This initial note demanded $20,000 from the family in exchange for Charley's safe return. 

Even though the family gave off signs of wealth with their large home in Germantown, they were actually in debt due to the stock market crash, according to the Crime Museum. 

The Ross father was unable to afford the ransom and instead, contacted the police. There wasn't any progress made in the case until later in the year, when police were investigating a different kidnapping. Police were able to match a ransom note in association with the case to the handwriting from the note sent to Charley's family. 

The handwriting was identified as one belonging to the fugitive convict William Mosher, according to the Crime Museum. 

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Mosher had been killed during a burglary in Brooklyn, but his crime partner, Joseph Douglas, who was shot in the incident, confessed that they had been responsible for Charley's abduction, according to the Library of Congress. Douglas said Mosher was the only one who knew where Charley was being held. Douglas died just a couple of hours after giving this information. 

For the remainder of his life, Christian continued the search for his son. In total, he spent $60,000 on search efforts. 

In 1876, he wrote the book "The Father's Story of Charley Ross, the Kidnapped Child," and used the money to continue with the search for his son, according to the Library of Congress. 

Over the years, there were several impostors who claimed to be Charley, but the family was never reunited. 

Christian died in 1897 and his wife died in 1912. Charley's brother Walter died in 1943. 

To this day, it is still unknown what really happened to Charley.