The most frequently issued denomination within the classic-era US commemorative coin series was undeniably the Silver Half Dollar; the Gold Dollar was next in line. For the modern series, the Silver Dollar has been the most often used, with the Gold Half Eagle ($5) slotting in behind it.
The Eagle ($10) is the least-used denomination of the modern series, being used for just three coins to date:
- 1984 Los Angeles Olympics

- 2000 Library of Congress Bicentennial

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- 2003 Wright Brothers' First Flight Centennial
Note 1: Some collectors will include the 2020 Gold $10 Mayflower 400th Anniversary Gold $10 coin on this list, but as it was struck by the US Treasury/ US Mint under its own authority vs. being a Congressionally-authorized commemorative coin, I'm leaving it off the list.As the Gold Half Eagle ($5) is codified as the standard piece/denomination for modern US gold commemorative coins, including a Gold Eagle ($10) in a commemorative coin program requires specific language in a bill to authorize its use. For this reason, future issue of $10 US commemorative coins is likely to remain an infrequent occurrence.
Note 2: The Gold "First Spouse" series of $10 coins is viewed by some as a commemorative series, but I contend, in fact, that it is a thematic series that is comprised of sequential issues linked by a "First Spouse" theme, not specific dates to be commemorated with coins on important anniversaries of such dates. Yes, it can be argued that each "commemorates" a particular First Spouse, but, IMO, as with the Statehood Quarter series, the coins do not specifically mark historic anniversaries/events but rather represent a chronological list of elements from a linked theme.I own one coin from the First Spouse series, the 2007 Thomas Jefferson coin. I bought it because I liked its use of a classic
Liberty design. As Jefferson was not married when he was US President (1801-1809) - his wife, Martha Wayles Skelton, died September 6, 1782 - the potential gap in the thematic series was filled with a classic
Liberty design on the obverse. (The same approach was used for the 2008 Andrew Jackson, 2008 Martin Van Buren and 2010 James Buchanan coins.)
2007 Thomas Jefferson - "First Spuse" - Gold Eagle