The greenback was trying to steady Friday against many of the world's major currencies, but its Canadian counterpart continued to strengthen to levels not seen since the mid-1970s.
Euros were trading at $1.4075 recently, down slightly from $1.4076 late Thursday.
As for the Candian dollar, one greenback was buying only C$0.9996, down from C$1.0006 a day ago.
Marco Spaltro, a currency economist at IDEAglobal in New York, said the Canadian currency is getting a lift from the strength in oil prices, which will boost foreign exchange earnings of the resource-rich economy.
Elsewhere, the dollar was worth 115.54 yen, up from 114.42 yen a day earlier. The pound was selling for $2.0204, up from $2.0096 previously. The Australian dollar was unchanged.
The big downward move in the dollar this week was prompted after the Federal Open Market Committee slashed key interest rates Tuesday, says Meg Browne, a currency strategist at Brown Brothers Harriman in New York.
Foreign exchange investors are particularly sensitive to changes in the returns on holding different currencies. So the larger-than-expected drop in the cost of borrowing led many investors to dump dollars in favor of other currencies.
The next downside price target traders are looking for on the European common currency is $1.45, based on how the value of the "synthetic" euro moved during the 1990s, Browne says.
Meanwhile, traders will be awaiting next week's release of new data on consumer confidence and final government figures showing how fast the economy grew in the second quarter.
The exchange-traded funds that track the currencies, such as the
CurrencyShares Canadian Dollar Trust
CurrencyShares Euro Trust
, were moving in line with the spot market action.