The first U.S. half dollar was issued in 1794 so there can't be a 1776 half dollar.
If you have a large (30 mm) coin with a picture of President Kennedy on the front, it's a dual date (1776-1976) Bicentennial commemorative. (After all, JFK was born in 1917 so there's no way his picture could be on a real 1776 coin!) If you have a Bicentennial coin please see the related question.
The other possibility is that you have a privately-minted medal, token, or fantasy piece. Unless it contains silver, these have little collector value.
Please look at your coin a bit more carefully. The date is 1776-1976. Your half dollar is one of a huge number minted as part of the Bicentennial celebration; if you found it in change it has no extra value. A nice uncirculated one might sell for $1 or so.
MoreThe US struck special dual-dated quarters, halves, and dollars for the Bicentennial. The coins were made in both 1975 and 1976 but all carried the same dual date. So many were made, and so many were saved as keepsakes, that the only ones worth more than face value are either uncirculated specimens or special collectors' versions that were sold in special packages.50$
A US half dollar with a date of 1979 is a Kennedy half dollar not a liberty half dollar. The coin has no silver and is only face value.
It has a metal value of about $10.
Value is for the silver about $2.50
About $4-5
50 cents.
a half dollar
The US didn't strike any half dollars in 1804.
A U.S. half dollar dated 1953 or 1952 is a Franklin half dollar. If it shows any wear, the value is only for the silver, about $10.00. The coins are very common.
A US half dollar with a date of 1983 is a Kennedy half dollar not a liberty half dollar.The coin has no silver and most are only face value.
The value of a US 1964 half dollar in circulated condition is around $10. in uncirculated condition they are worth around $16.
50 cents.