The provided search results do not contain specific information to answer the question, as they consist primarily of website navigation links rather than substantive content about coin values. Based on general numismatic knowledge, the value of a United States half dollar is determined by several key factors, including its age, rarity, metallic content, and physical condition.
Historically, the most fundamental factor contributing to a half dollar's value is its silver content. Half dollars minted in 1964 or earlier are composed of 90% silver, giving them a baseline value tied to the spot price of the precious metal. From 1965 to 1970, the composition was changed to 40% silver, which still provides intrinsic value above face value. Half dollars minted for circulation from 1971 onward contain no silver and are generally only worth their fifty-cent face value unless they are in uncirculated condition or are a rare variety.
Beyond bullion value, certain series and specific issues command significant numismatic premiums. Early designs, such as the Flowing Hair (1794-1795) and Draped Bust (1796-1807) half dollars, are exceptionally rare and valuable in any condition due to their age and low mintage numbers. Later series, including the Capped Bust, Seated Liberty, and Barber half dollars, also contain numerous "key date" coins—issues from a particular year and mint—that were produced in very small quantities and are highly sought after by collectors.
The Walking Liberty half dollar series (1916-1947) is widely collected, and while common dates are often traded for their silver content, coins in high-grade, uncirculated condition can be quite valuable. Specific dates like the 1921-S and 1938-D are notable rarities within this series. Similarly, while most Franklin half dollars (1948-1963) are valued for their silver, pristine examples with a clear "Full Bell Lines" strike detail on the reverse are worth considerably more. For the Kennedy half dollar series, the 1964 issue is 90% silver, but certain later proof coins, special mint set issues, and error coins can also carry a significant premium over their face or melt value.
