Chancellor Joel Klein, in a speech to the American Enterprise Institute in Washington, D.C., tomorrow, will present as a broad success story his six-year tenure running the city’s schools.

The speech will tell the story of the overhaul that began when Mayor Bloomberg won control of the public schools in 2002 and appointed Mr. Klein, then a former Justice Department attorney who had won some attention by challenging Microsoft, as chancellor.

His last previous experience in New York’s system had been when he attended Queens public schools growing up.

The lack of education background riled many educators in New York, and over the years parents and elected officials have challenged Mr. Klein’s policies, while his public approval ratings have been below those of other prominent citywide officials. (A recent Quinnipiac poll showed that 37% of voters approve while 41% disapprove of the job he is doing.)

Mr. Klein has received high praise outside the city, most recently winning the Broad Prize for best urban school system and by playing a role in Mayor Adrian Fenty’s choice of schools chancellor for Washington.

The new chancellor in Washington, Michelle Rhee, cites Mr. Klein as a mentor.

Accountability and empowerment are the two main ideas Mr. Klein will discuss in his speech, explaining that he has tried to give principals more flexibility on the one hand while holding them to higher standards on the other.