If your coin has been gold plated, it has lost its collector value and would now be considered a novelty item -- value about $10 1900-O and 1901-O are not rare dates for Morgan Dollars. In circulated condition, they're worth about $12 each. Nice uncirculated ones are worth about $35 each.
No, no dollar coins were minted there in 1847. Early silver dollar production at New Orleans was intermittent. They were only struck there in 1846, 1850, 1859, and 1860 before the Mint was captured by the Confederacy. Following the Civil War dollar production at New Orleans was much more frequent.
If it's a gold-colored "Loon" dollar, it has no silver at all. "Loonies" minted in 2001 are made of brass-plated nickel.
Trade dollars were US coins made in silver to trade in the far East. However, your coin, if it is an 1884 Trade Dollar, it is counterfeit. There were only 10 examples minted that year, all of them are known. So, when it comes to value, the only value your coin can have is if it is minted in real silver, if it is minted in real silver, it is worth however much silver is in your coin. If it is silver plated lead, or silver plated copper, or non-silver alloy like "nickel silver" your coin is essentially worthless.
The last silver half dollar was minted in 1969.
The "O" mintmark identifies the Mint at New Orleans, LA
The coin is common, circulated examples are $17.00-$26.00 retail.
Silver Dollars were minted starting in 1794. There were no silver dollars minted in 1791
There was no 1999-O dollar minted. The O mint mark signified the New Orleans Mint, which closed down 90 years earlier. The only dollars minted by the US Mint were the Susan B. Anthony dollar, which contained no silver at all, and the American Silver Eagle, which contained roughly 1 oz. of silver.
The first Morgan was struck in 1878 and no silver dollars were struck at the New Orleans Mint in 1865. Look at the coin again and post new question.
No
Not enough details. New Orleans minted Morgan dollars from 1879 to 1904. Please post a new question with the coin's date.
There was no silver dollar minted in the U.S. in 1958.