According to Knerr authority James Lowe, Knerr was extremely prolific, producing more than 1,500
Sunday comic pages between 1901 and 1914 for a half-dozen continuing features in three different Philadelphia newspapers. He created his first comic strip,
Zoo-Illogical Snapshots, for the
Public Ledger. In 1899, when he was 18, he started working for
The Philadelphia Inquirer. In 1901, he drew the
Sunday strip, ''Willie's Revenge
, followed by a number of comic strips, including the Mr. Jack-inspired Mr. George and His Wife
(1904–14). In 1906, he took over the strip Scary William
and continued it until 1914. From June 15, 1913 to November 15, 1914, he drew The Irresistible Rag
. (The cartoonist Joe Doyle drew both Scary William
and The Irresistible Rag'' after Knerr left these strips.) From 1903 to 1914, he drew
The Fineheimer Twins, an imitation of
The Katzenjammer Kids, which made it obvious he was the ideal artist to replace
Rudolph Dirks on
The Katzenjammer Kids. ==
The Katzenjammer Kids==