The phrase "an unprecedented effort" is correct and usable in written English.
It can be used to describe a significant or extraordinary attempt or endeavor that has not been seen before.
Example: "The organization launched an unprecedented effort to combat climate change, rallying support from communities worldwide."
Alternatives: "a historic effort" or "an extraordinary effort".
"This is an unprecedented effort in terms of what's going into the launch," he says.
The Israeli Parliament's antiboycott legislation is an unprecedented effort to undercut nonviolent resistance to Israeli oppression.
issued an international appeal that galvanized global cooperation in an unprecedented effort to contain the dangerous disease.
Rogge cited an "unprecedented effort" by the Greek government and a seven-nation advisory group to provide security.
What's most galling about this corrupt behavior is the fact that the current government is making an unprecedented effort to confront poverty.
Kirchner and her husband had long presented themselves as the moral censors of the country, leading an unprecedented effort to confront Argentina's history of political violence.
Some of them believed those skills would be particularly important in the coming years as the Fed unwinds its huge stimulus campaign, an unprecedented effort with unknowable complications.
"The mandate", began Mr Clement, "represents an unprecedented effort by Congress to compel individuals to enter commerce in order to better regulate commerce".
The plaintiffs characterized the insurance requirement as an unprecedented effort to regulate inactivity because citizens would be assessed an income tax penalty for failing to buy a product.
The battle against Lyme disease is just an early stage in an unprecedented effort to conquer some of mankind's most pervasive afflictions, such as malaria and dengue fever.
"We have mounted an unprecedented effort to recruit affinity groups," Michael Morell, the associate deputy director of the C.I.A., told me.
