WASHINGTON — The Federal Reserve said on Wednesday that it would raise short-term interest rates for the first time since the financial crisis, a decision it described as a vote of confidence in the American economy even as much of the rest of the world struggles.

The widely anticipated announcement — that the Fed would raise rates to a range between 0.25 percent and 0.5 percent — signals the beginning of the end for the central bank’s stimulus program. Fed officials emphasized that they intended to raise rates gradually, and only if economic growth continues. Short-term rates will rise by about one percentage point a year for the next three years, Fed officials predicted.

Interest rates on mortgages and other kinds of loans, and on savings accounts and other kinds of investments, are likely to remain low for years to come.