When incorporated in 1901, the village was known as Shermerville in honor of Frederick Schermer, who donated the land for its first train station. The village changed its name to Northbrook in 1923 as an effort to improve its public image. The name was chosen because the West Fork of the North Branch of the Chicago River runs through the Village.
History
Members of the Potawatomi tribe were the earliest recorded residents of the Northbrook area. In 1833 the Potawatomi ceded their Illinois lands and moved to a place near Council Bluffs, Iowa. Afterwards Joel Sterling Sherman and his family bought 159 acres (64 ha) of land in the northwest quarter of Section 10 for $1.25 per acre; as of 2010 Northbrook’s downtown is located on this site. A man named Frederick Schermer donated the land used for the first railroad station, named Schermer Station and later Shermer Station; the community was named Shermerville after him. By the 1870s Shermerville was a farming community. In 1901 the community was incorporated as the Village of Shermerville after a close referendum for incorporation. At the time of incorporation it had 311 residents and 60 houses. By 1921 residents believed that the name “Shermerville” had a negative reputation. A renaming contest was held, and a man named Edward Landwehr submitted the name “Northbrook”. In 1923 “Northbrook”, the winner, was adopted; at the time Northbrook had 500 residents. After the end of World War II, Northbrook’s population began to rapidly increase.

from Wikipedia