It's all about silver content, minting errors, and condition when it comes to the value of Kennedy half dollars.

Caroline Kennedy and Schlossberg will present the award to Pence on May 4 at the John F. Kennedy Presidential Library and Museum in Boston, Massachusetts.

The lot, officially titled "John F. Kennedy | J. Edgar Hoover Signed 1964 Assassination Letter and Other Signed Letters (3)," has a starting bid of $25.

About 99 percent of the government documents related to President John F. Kennedy’s assassination have long been available to the public under a 1992 law.