The oldest is the Ivory Quinby House at 605 North 6th Street, built in 1867 for Ivory Quinby, an early benefactor and founder of Monmouth College who also helped bring the Peoria and Oquawka Railroad through town. Chicago architect John C. Cochrane — who later designed the Iowa State Capitol — gave it an Italianate and Greek Revival design. The house stayed in the Quinby family until 1965, when it passed to Monmouth College; it’s still in use today as the college president’s residence.
Three more sit within a few blocks of each other on East Broadway. The Sarah Martin House at 310 East Broadway was built in the Italian Villa style between 1875 and 1878 for banker John Martin; his daughter Sarah inherited it at fourteen and became a well-known Monmouth socialite and musician, keeping the house until 1945. A few doors down, the William S. Weir Jr. House at 402 East Broadway (1894) is a Tudor Revival home built for a local investor whose plow-and-cultivator business had made him wealthy the decade before. Next to it, the Carr House at 416 East Broadway started out in 1877 with a simpler Second Empire design; an 1898 redesign for the Carr daughters layered in Classical Revival, Jacobethan, and Victorian Gothic details, making it — according to its own National Register listing — the only high-style eclectic home left in Monmouth.
The last two carry a different kind of significance: both are birthplaces of national sororities. The Stewart House, an 1865 Victorian at 1015 East Euclid Avenue, was the girlhood home of Mary Moore Stewart, who founded Kappa Kappa Gamma there with five classmates on October 13, 1870 — the sorority’s constitution was written and its charter signed inside the house. And on April 28, 1867, twelve Monmouth College students meeting in a second-floor bedroom of the Holt House, at 402 East First Avenue, founded I.C. Sorosis, known today as Pi Beta Phi; the house was restored and reopened as a memorial in 1941, and the Illinois State Historical Society named it a landmark in 2009.
Of the six, only the Stewart House and Holt House are regularly open to visitors — the Stewart House operates as a museum (Wednesdays and Fridays, 10 a.m.–4 p.m.) and the Holt House is open to the public as well. The other four are private residences, or in the Quinby House’s case, the college president’s home — best appreciated from the sidewalk rather than toured.