Gen. William Worth Belknap House

The Frank J. Weess House is a historic building located in Keokuk, Iowa, United States. Built from 1880 to 1881, it is considered a fine, although a rather restrained, example of the Second Empire style. The relative restraint of the rest of the house allows the architectural focus of the structure to be its rather elaborate main entrance and front porch. The two-strory brick structure is capped by a mansard roof with bracketed eaves and pedimented dormer windows. The windows on the rest of the house are capped with stone hoods. It was listed on the National Register of Historic Places in 1978. Frank J. Wees was a native of the Netherlands and came to the United States in 1849. He was a butcher by trade and by 1860 he established a successful meat business in Keokuk. He also owned considerable amounts of real estate in the area.

Lock and Dam No. 19 is a lock and dam located on the Upper Mississippi River near Keokuk, Iowa. In 1978, the Keokuk Lock and Dam was listed in the National Register of Historic Places, #78001234. In 2004, the facility was listed in the National Register of Historic Places as Lock and Dam No. 19 Historic District, #04000179 covering 1,605 acres (650 ha), 7 buildings, 12 structures, 1 object. The lock is owned and operated by the U.S. Army Corps of Engineers. The dam is owned and operated by Ameren Missouri. The lock and dam obliterated the Des Moines Rapids which had effectively been the northern barrier for traffic on the Mississippi until efforts began in 1837 to address the Mississippi's 2 ft 6 in (76 cm) depth in the rapids.

The Gen. Samuel R. Curtis House is a historic building located in Keokuk, Iowa, United States. Samuel R. Curtis was an engineer, congressman and served as mayor of Keokuk in the 1850s. He was the hero of the Battle of Pea Ridge during the American Civil War. Curtis was the first Major General from Iowa during the war. Curtis had this Greek Revival house built about 1849. The significance of the house is its association with Curtis, who died in 1866. It remained in the Curtis family until 1895 when it was sold. The house was listed on the National Register of Historic Places in 1998. The house is a two-story rectangular limestone structure. When it was built it was L-shaped, but an 1857 renovation brought it to its current shape. It features a full-width front porch supported by Ionic columns and Adamesque details that was part of a later renovation. It has a walk-out basement in the back. In the back of the property is a two-story carriage house, which is not a part of the house's historic designation because it was built after Curtis' death.

The Hugh W. and Sarah Sample House is a historic building located in Keokuk, Iowa, United States. Hugh Sample became the mayor of Keokuk in 1858 and had the house built the following year. He lived in the residence until his death in 1870. The 2½-story structure was designed in the Italianate style and is considered the finest and most intact example of that style in Keokuk. It follows an irregular plan and features tall narrow windows capped with elaborated crowns, a low pitch gabled roof, and wide bracketed eaves. At one time the house had an ornate cupola. The rooms on the interior have 12-foot (3.7 m) ceilings The house was listed on the National Register of Historic Places in 1995.

The Justice Samuel Freeman Miller House is a historic building in Keokuk, Iowa, United States. It is now operated as the Miller House Museum by the Lee County Historical Society. The significance of this house is its association with Samuel Freeman Miller who had it built. Originally from Kentucky, he was a physician and a lawyer with a national reputation. Miller was nominated by President Abraham Lincoln to serve on the United States Supreme Court in 1862. His was the first nomination to the court of a person who resided west of the Mississippi River. He served on the court for 28 years. Although he lived here for only two years, Miller always considered this his home. The house is a two-story structure designed in the Italianate style. It has an exposed basement on the rear of the structure. The brick residence is capped with a low-pitched hip roof and bracketed eaves. The bracketed porch on the main level features a balcony on the second floor. The house was listed on the National Register of Historic Places in 1972.

St. John's Episcopal Church is a parish church in the Episcopal Diocese of Iowa. It is located in Keokuk, Iowa, United States. It was listed, together with the parish hall, on the National Register of Historic Places in 1989.

The John N. and Mary L. (Rankin) Irwin House is a historic building located in Keokuk, Iowa, United States. It was individually listed on the National Register of Historic Places in 1999. In 2002 it was included as a contributing property in The Park Place-Grand Avenue Residential District.

The E. H. Harrison House is a historic building located in Keokuk, Iowa, United States. It was designed in a combination of Federal, Greek Revival, and Second Empire styles by local architect Frederick H. Moore, and built in 1857 by local builder R.P. Gray. It is believed that this is the first house in Iowa to have a Mansard roof, which is its Second Empire influence. The Federal style is found in the building's large windows, the elliptical doorway arch, the bowed two story front bay, and the brickwork. The Greek Revival style is found in the offset doorway. Its interior features a unique open, two-story, self-supporting staircase that is said to be one of seven in existence in the United States. Additions have been built onto the back of the house, but their dates are unknown. The man who had the house built was Enos H. Harrison, who was a successful businessman originally from Elizabeth, New Jersey. He and his family settled in Keokuk in 1849. In Iowa, he helped establish the Keokuk Branch of the Iowa State Bank where he served as its first president. He also helped to establish the waterworks in Keokuk and the Iowa State Insurance Company. Harrison was involved with other business interests and the local Unitarian Church, which was located next door. He also served four terms as First Ward Alderman in Keokuk. Harrison died here in 1877, and the family sold the house. It was converted into offices around 1967. The building is said to be haunted by a friendly ghost, although it reportedly chased out one of the building's tenants. It was listed on the National Register of Historic Places in 1984.

The Keokuk Young Women's Christian Association Building is a historic building located in Keokuk, Iowa, United States. It was listed on the National Register of Historic Places in 2004. The local YWCA was organized in 1905 and initially leased space for their activities. The land for this building was donated by Gerard Huiskamp. Completed in 1913, the building was designed by local architect Harry E. Ratcliffe. It is representative of transitional architecture in the early 20th century. The two-story brick structure is built on top of a full basement. It features Art Deco tile ornamentation. The exposed basement level is concrete that is designed to look like stone. In addition to the YWCA, the building served as a hub for social activities in the community. It was home to the YWCA for nearly 50 years until it merged with the YMCA, which sat across the street. From 1953 to 1975, both buildings were used by the combined organization. In 1975 a modern facility replaced the two older buildings, and the former YMCA building, which had been built in 1899, was torn down that year. In 1976 the first floor of the former YWCA building was renovated for use as the courthouse for southern Lee County. Those functions were transferred to the former United States Post Office and Courthouse in 1994.

The Alois and Annie Weber House is a historic building located in Keokuk, Iowa, United States. The significance of the three-story house is its association with the period of industrial growth in the city when it was built and as a fine local example of the Second Empire style. It features an asymmetrical concave mansard roof, decorative brackets, and pedimented dormer windows. The house is noteworthy for its tall narrow windows and high ceilings. Two additions were added to the rear of the house not long after the main house was built. The Queen Anne-style wraparound porch is supported by 14 classical columns. It also features a balustrade and spindlework along the beadboard ceiling. The house was listed on the National Register of Historic Places in 2002. Alois Weber founded A. Weber & Co., a hardware business and was known throughout the Midwest. He ran the business until his death in 1917. His wife Annie owned a millinery shop from 1856 to 1887. She died in 1898.

The Hotel Iowa, now known as the Historic Hotel Iowa, is a historic building located in downtown Keokuk, Iowa, United States. It was built from 1912–1913 and it was listed on the National Register of Historic Places in 1987.

The C. R. Joy House, also known as The Grande Anne Bed & Breakfast, was a historic building located in Keokuk, Iowa, United States. It was destroyed by fire in July 2018. It was individually listed on the National Register of Historic Places in 1997. In 2002 it was included as a contributing property in The Park Place-Grand Avenue Residential District.