The Ogle County Courthouse was designed by Chicago architect George O. Garnsey in the Romanesque Revival style of architecture.

The courthouse no longer serves as the primary judiciary center for the county; its successor is located directly across the street.

The current structure on the public square, no longer in use as the judiciary center in Ogle County, was constructed in late 1890 and early 1891 at a cost of US$107,000.

[3] The basically square Romanesque Revival structure is topped with a cupola and features a full basement.

On March 21, 1841, the night before court convened in its new building, the bandits allegedly set the courthouse on fire, completely destroying it.

The defendants were provided with counsel and the trial ensued, which residents involved called "fair" at the time.

Ogle County communities, Byron, Mount Morris, Grand Detour and Daysville were all in contention for the designation, and, ultimately, the new courthouse.

At the deciding meeting the representatives from Daysville removed their town from the running and sided with Oregon.

Some of the 1848 building's architectural elements included, a vent cupola, double-hung sash windows, complete with shutters, a gabled front roof and corniced returns.

[3] Today, events no longer regularly take place on the courthouse lawn, but some festivals still occur at the location.

"[3] Inside the courthouse, each office and courtroom was renovated, the exterior of the structure was refurbished and restored as well.

[3] This example of Romanesque Revival architecture was designed by George O. Garnsey, a Chicago architect well known in northern Illinois.

The building is constructed of red pressed brick, detailed with locally quarried limestone, and reinforced with steel girders.

[2][4] The red brick facade is detailed with significant amounts of limestone, including in its continuous lintels and sills.

At each of the square shaped building's four corners are dormers, which serve to break up the monotony of the otherwise ridged roof.

[6] The public square where the Ogle County Courthouse stands is in the heart of the Oregon Commercial Historic District.

Besides the courthouse, there are five other important sites on the public square, all of which are considered contributing properties to the historic district.

Iron Mike, the 1896 cast-iron fountain, is on the south side of the 400 Block of Washington Street in the Oregon Commercial Historic District.

[2][4] On the north side of the public square is a terraced concrete memorial dedicated to Ogle County veterans of wars other than those included on The Soldiers' Monument.

[2] On its original National Register nomination form the building was cited as significant in the areas of "architecture" and "politics and government."

The courthouse has been called a "prized landmark," and a site "that holds a special place of honor" in the city of Oregon.

[3][4] Three of the features on and around the courthouse grounds, Iron Mike, the War Memorial, and The Soldiers' Monument, all greatly contribute to the sense of time and place that the Oregon Commercial Historic District conveys.