When was silver taken out of the silver dollar?

Answer 1

All genuine US silver dollars were made of an alloy of 90% silver and 10% copper. They were minted until 1935.

New circulating $1 coins were issued in 1971. Many people used the old term "silver dollar" for these coins, but all of the ones issued for circulation were made of copper and nickel until 1999; new ones are made of brass. Some Eisenhower dollar coins made in the early 1970s were struck in 40% clad silver but these were only sold to collectors.

An interesting side note is that a trial run of about 300,000 90% silver dollars was made in 1964 but none of these were ever put into circulation. Supposedly all were melted but rumors persist that a few were clandestinely saved.