Orson Lowell, 1871-1956, was a master draftsman considered to be in many ways superior to Gibson in his pen-and-ink renderings, but he didn't have the clout that Gibson had. Personally, I think it's more about the characters than technique. The Gibson Girl seemed to have personality that transcended the medium of print. She was to artwork what Marilyn Monroe and Brigitte Bardot were for photography.
May Wilson Preston, 1873-1949, was her own person, strong-willed and dynamic, and a fighter for women's rights. It's evident in her style that is not in the least derivative. She owed nothing to Gibson, despite his enormous influence at the time.
May Wilson Preston is one of my favorites and I hope to be posting more of her work soon. Click on image to enlarge.
Harrison Fisher, 1875-1934, got in the American Girl theme and segued from magazine illustrations to portraits of celebs.
Howard Chandler Christy, 1873-1952, was another. This is not one of his best and the reproduction is messy. He did a lot of very nice portraits after he left the magazine business. One of his finest is that of First Lady Grace (Mrs. Calvin) Coolidge. Here's another link to more of his work.
James Montgomery Flagg, 1877-1960, was a child prodigy who sold his first illustration at the age of 12, according to his bio in this hotlink. He was a blatant imitator of Gibson and probably got a lot of work because of the astronomical (at the time) prices that Gibson demanded.
He was even signing like Gibson in this illustration for the December 1906 issue of Scribner's.
By August of 1907 he was using a signature that was much more legible and certainly helped to establish his bona fides. Click on these images to enlarge.
This is from Scribner's of February 1909.
Finally, Monty Flagg's most famous illustration, produced to promote enlistments in the U.S. military at the time of World War I. It has become an icon for almost a century.
Another of my favorites is Florence Scovil Shinn, 1871-1940. She obviously didn't feel compelled to scratch away with her pen in homage to Gibson. She, too, will reappear in these postings at a later date. She became famous in a later career as a motivational writer and speaker.
She was one of four wives of the notorious Ashcan School painter Everett Shinn, 1876-1953.