promoter, booster, plugger
Meaning: someone who is an active supporter and advocate
"Practical affairs," he said, with a wave of his hand toward the promoter, "are, if I may use the comparison, the garden walks upon which we tread through life, viewing upon either side of us the flowers which brighten that journey.
He came out of that flushed and capable region known as the "North." He called himself a "promoter"; his enemies had spoken of him as a "grafter"; Okochee took a middle course, and held him to be no better nor no worse than a "Yank."