The Rev. Jesse Jackson said he learned an early life lesson when his high school football team traveled from Greenville, S.C., to play Howard High School in Chattanooga more than a half century ago.

A school janitor at Howard told the rowdy visitors upon their arrival to watch their language and behavior "because we expect the best" from students and staff.

"There was respect, not just for the teacher who might give you a grade, but for the cooks, janitors and other adults at Howard High," Mr. Jackson recalled Friday while in Chattanooga.

Although Howard School of Academics and Technology now has the district's lowest graduation rate and is among the state's most troubled schools, Mr. Jackson told Howard students Friday he believes the school is doing better and can still be among Tennessee's best.

During a midday rally complete with a band and majorette entrance, the civil rights leader appealed to Howard students to stay in school, study hard and get involved.

"I want everyone of you to leave this school with a diploma in one hand and a voter registration card in the other," he said.

When Howard football senior Chris Deloney told Mr. Jackson the team typically practiced two to three hours a day during football season, Mr. Jackson told students they need to spend at least as much time on their homework "without turning on the TV, listening to the radio or calling your boyfriend or girlfriend."

Chris, who has committed to play football for Tennessee State University, said he usually spends an hour a night on his homework.

"There is no reason that 100 percent of you shouldn't graduate," Mr. Jackson told the students before leading them in a commitment to take pride in themselves, stay off drugs and respect "the good work being done" by Howard principal Paul David Smith.

Mr. Jackson noted that Howard has boosted its graduation rate from a low of about 25 percent to 56.5 percent last year. State test scores also show math achievement increased last year at Howard from 51 percent to 72 percent and reading scores rose from 83 percent to 94 percent.

But Howard still is far below the federal standards set by No Child Left Behind and is one of 13 schools identified as failing by the state.

Nearly half the students at Friday's rally stood up when Mr. Jackson asked them if they knew of someone who had brought a gun to school. More than a dozen stood up when asked if they knew of someone who had died from a drug overdose.

Mr. Jackson, the founder of the Rainbow/PUSH Coalition who twice ran for president, ended the student rally with a prayer and an altar-like call for students who will be 18 years old by November to come forward and register to vote.

Although the Hamilton County Election Commission offers voter registration at schools during the winter, more than 50 juniors and seniors filled out voter registration cards Friday.