Coin history and collecting

General articles on U.S. coin history, grading and collecting. They are for education only and are not an appraisal of any coin.

• How to read a U.S. coin's mint mark
  Mint marks show where a coin was struck. Here is what the letters mean.
• What the Sheldon grading scale means
  Coins are graded on a 1 to 70 scale. Here is how to read the numbers.
• What a graded coin slab is
  A slab is a sealed holder with a grade label. Here is why collectors like them.
• What CAC approval means
  CAC is a sticker program for coins that are already graded. Here is what it adds.
• Why cleaning coins hurts their value
  Cleaning a coin can leave marks that collectors can see. Here is why it matters.
• What coin toning is
  Toning is the natural color change that builds up on a coin over time. Here is how to think about it.
• Proof coins versus business strikes
  Proof coins and business strikes look different. Here is how to tell them apart.
• The history of the Morgan silver dollar
  The Morgan dollar was struck from 1878 to 1921. Here is the story behind it.
• The history of the Peace silver dollar
  The Peace dollar was struck from 1921 to 1935. Here is what it marks.
• The Walking Liberty half dollar
  The Walking Liberty half dollar was struck from 1916 to 1947. Here is a short history.
• The Standing Liberty quarter
  The Standing Liberty quarter was struck from 1916 to 1930. Here is the story of its design change.
• The Mercury dime, and why it is called that
  The Mercury dime was struck from 1916 to 1945. Here is why the name is a mistake.
• The Buffalo nickel
  The Buffalo nickel was struck from 1913 to 1938. Here is what collectors look for.
• The Indian Head cent
  The Indian Head cent was struck from 1859 to 1909. Here is what it shows.
• The Lincoln cent, from 1909 onward
  The Lincoln cent was introduced in 1909. Here is how it began.
• Gold coinage in the United States
  Gold coins were central to U.S. money for much of its history. Here is an overview.
• The Saint-Gaudens double eagle
  The Saint-Gaudens double eagle was a $20 gold coin struck from 1907 to 1933. Here is its history.
• Silver in Kennedy half dollars
  Kennedy half dollars were struck with silver for several years. Here is what changed.
• The Eisenhower dollar
  The Eisenhower dollar was struck from 1971 to 1978. Here is a short history.
• Low mintage does not always mean valuable
  A small mintage can help a coin's value, but it is not the whole story. Here is why.