In the 1870s the Stockbridges moved to Kalamazoo. They lived in a hilltop house at 120 Carmel Street, near West Main Street, which became a center of local social life and political activity. The home became a local landmark, known for housing a valuable collection of paintings and pottery. His wife Betsey lived there off and on until her death in 1904. Kalamazoo College purchased the house in 1922 and used it for campus housing and classrooms. Eventually it was boarded up, fell into disrepair and was demolished in 1940.
Stockbridge lived in Kalamazoo for the rest of his life, but he moved his lumber operations further north, to St. Ignace, Michigan, closer to the remaining trees. He formed the Mackinac Lumber Company, and had many other business interests including the Menominee River Company, and the Black River Lumber Company. He also served as president of the Kalamazoo Spring and Axle Company and maintained interests in pine forests in Mississippi, west coast lumber companies, and Upper Peninsula iron mines.
In addition to his business interests, Stockbridge also got involved in politics, serving as a Republican in the Michigan House of Representatives and then the Senate from 1869 to 1873. He was later elected to two terms as a United State senator, serving from 1887 until his death in 1894. Livingstone's History of the Republican Party said that "he was distinguished for his tact as an organizer, his calm insight and prudence as a manager, and his great ability in committee work in every form."
The Grand Hotel
In 1882, Stockbridge purchased land on Mackinac Island, which had a splendid view of the Straits of Mackinac, with the intent of building a large hotel. Two years later he and his wife had a handsome summer "cottage" built just to the west. Stockbridge is widely regarded to be the guiding force behind the construction of the Grand Hotel, which was built on this site. The Michigan Central Railroad, the Grand Rapids & Indiana Railroad, and the Detroit & Cleveland Navigation Company steamship line formed a stock corporation called the Mackinac Hotel Company for the purpose of enticing Stockbridge to sell the land to the corporation. They wanted to build a hotel to attract summer tourists to the region. The sale of the land was contingent on Stockbridge's approval of the hotel plans. He rejected many offers because the hotel plans he saw were “not grand enough.” Finally a design by George Mason of Detroit pleased all concerned, so the land was sold to the corporation. Construction began in 1886, and the Grand Hotel opened on 10 July 1887. A hotel management firm was hired to operate it. Over the years Michigan’s most famous hotel has hosted presidents, celebrities, and political hopefuls. The Grand Hotel is best known for its long front porch. At 660 feet, it is supposedly the longest in the world.
In addition to his other business and political interests, Stockbridge loved fast horses. He had a financial interest in the widely known S. A Browne & Company of Kalamazoo, which specialized in raising fine race horses. As charitable as they were social, the Stockbridges also made generous donations to the Children's Home of Kalamazoo, the Academy of Music, the local YMCA, and Kalamazoo College among other things.
The senator died in Chicago on 30 April 1894 after a brief illness, and was buried in Mountain Home Cemetery. His name continues in Stockbridge Avenue in Kalamazoo's Edison Neighborhood.