The value of a $1 coin in the United States varies dramatically based on the coin's design, date of issuance and condition. For example, as of 2015, the U.S. Mint is releasing presidential dollar coins as a part of their presidential series that are currently worth their face value of $1.
A gold dollar issued between the years of 1849 and 1854 can be worth anywhere from a couple hundred dollars to over a million dollars, as of April 2015. An 1849 coin with the open wreath design has an approximate worth that varies from $200,000 to $1,200,000 as of April 2015, as stated by USA Coin Book, a site that specializes in coin collecting. Coins on the higher end of the range are in impeccable condition.