History of South America

What is the value of a 2002 Liberty quarter with back eagle upside down or 1977 no D letter and also down?

The 2002 Liberty quarter with the back eagle upside down is known as an "Upside Down Flying Eagle" error coin and can have significant numismatic value depending on its condition and scarcity. The value of such an error coin can range from a few dollars to several hundred dollars or even more for particularly rare specimens.

Similarly, the 1977 no D letter quarter with the down error, commonly known as the "Upside Down D" or "DDR (Double Die Reverse)" error, also has numismatic value. The degree of doubling and the strength of the reversed D determine the value of these error coins, which can range from a few dollars to several thousand dollars based on their rarity and condition.

However, it's essential to authenticate and grade any potential error coins by reputable numismatic experts or organizations to accurately determine their value, as authenticity and grading play a crucial role in establishing the exact worth of such numismatic collectibles.