By Greg Wood
North America business correspondent, BBC News, New York
Passing the bail-out bill is only the first step in a lengthy process.
Now that President George W Bush has signed the $700bn bill to buy bad assets from the banks into law a new question arises - will it work?
The plan is for the banks to sell their mortgage-backed securities in a series of auctions. The first is not likely to take place for at least a month.
That's because private financial firms will have to be hired to handle the process.
Up to 10 asset management companies will be used by the US Treasury.
The Treasury will also have to take on new staff to write the rules of the auction process and make sure the private firms running it don't abuse their position.
There will be a huge amount of interest in the first auction to see if it works and what sort of price buyers are willing to pay for these toxic assets.
The Treasury has up to $700bn to spend but it hopes that other, private buyers will also emerge.
The passing of the bail-out plan is just the first stage.
One leading US investment firm said there was a very large pool of private capital available to buy distressed mortgage-related assets now that the Treasury had put a floor under the market with the bail-out deal.
If this auction process is typical, buyers will bid the price they want for the amount of mortgage-backed securities they want, and those securities will be allocated to buyers at the highest price which ensures that they're all sold.
Banks have typically marked down the price of their mortgage-backed securities to around 20% of their face value.
So for the banks to obtain any relief, the auction process will have to obtain a price higher than 20 cents on the dollar.
If no private buyers are willing to pay that price at auction, then the US Treasury will have to use taxpayers' money to pay above the market price for toxic assets in the hope that they appreciate in value over the next few years.
The key indicator of whether the plan is working will be what happens to the rates the banks charge each other for borrowing money - interbank rates. They are currently sky high.
The banks don't want to lend other banks when they don't know what toxic assets they may be holding.
If the auction process helps to put a reasonable price on those assets and take them off the banks' balance sheets, then interbank rates should fall, easing up the flow of credit throughout the economy.
So it's a long and complex process. The passing of the bail-out plan is just the first stage.
And it will be several months before we can tell whether it's working or not.