He was the first and, until the election of Demond Meeks in 2020, only black person to represent Monroe County in the New York Assembly.

During his tenure in the Assembly, he served on the Aging, Commerce, Election Laws, Steering, Transportation, and Ways and Means committees.

In 1960, he graduated from Franklin High School, and later he attended the Roberts Wesleyan College and Rochester Institute of Technology.

[5][4] Gantt attended Roberts Wesleyan College for two years using a partial basketball scholarship, but dropped out due to the financial constraints on his family.

[6] After dropping out of college, he worked for Case-Hoyt Corp. printing company and as a manager at the Anthony Jordan Health Center.

[2] In 1973, Gantt ran to succeed Good in the Monroe County Legislature from the 22nd district, defeating Republican nominee Leonard M.

[15] In 1977, the Democratic minority in the county legislature attempted to place him onto the Ways and Means Committee, but the Republican majority rejected Gantt in favor of Anthony Reed.

[17] In 1980, Gantt was elected as a member of the New York Democratic Party's state committee alongside Marlene Tisdale.

[18] On July 15, 1982, Gantt announced that he would seek the Democratic nomination in the New York Assembly's 133rd district to replace Assemblymember Dale Rath.

[47] In 1989, he was selected to serve as the chairman of the state Legislative Commission on the Development of Rural Resources by Speaker Mel Miller.

[58] Following his death, he was praised by Governor Andrew Cuomo, Attorney General Letitia James, United States Representative Joseph Morelle, Assembly Speaker Carl Heastie, Assembly Minority Leader William Barclay, and Rochester Mayor Lovely Warren.

[59] In 1994, Gantt voted in favor of legislation that would prohibit discrimination based upon sexual orientation in jobs, schools, public establishments, and housing.

[63] In 2001, Gantt co-sponsored a resolution by Charles H. Nesbitt that called for President George W. Bush to pardon the 50 black sailors who were convicted for refusing to load munitions onto ships following the Port Chicago disaster.

[68] In 1983, Gantt introduced legislation that would make the possession of a knife, dagger, or imitation pistol on school grounds a Class A misdemeanor punished with up to one year in prison and a $1,000 fine.

[69] In 1993, he sponsored legislation that would make the possession of a loaded gun in a school building, playground, athletic field, or within 1,000 feet of schoolyards a felony punishable with six to twenty five years in prison.

[71] In 2000, he voted in favor of legislation that raised the age requirement for obtaining a handgun permit from 18 to 21 years old.

[74] In 1995, he voted against legislation that would reinstitute capital punishment, but it was approved by the Assembly and Senate before being signed into law by Governor George Pataki.

[77] In 1993, Gantt proposed using $10 million to renovate the Silver Stadium to meet Major League Baseball facility standards and transfer ownership from the Rochester Red Wings to Monroe County.