As the county's primary courthouse for over 100 years, the site has been host to many trials, including prominent murder cases.

The rear facade of the building is designed to resemble a temple and also features stained glass windows.

During the early 1980s the made-for-television movie Will: G. Gordon Liddy filmed scenes in the DeKalb County Courthouse's courtroom.

A now defunct town called Brush Point was the choice of a Dr. Henry Madden and Rufus Colton would have preferred Coltonville, where he made his home.

His political tactics were eventually cancelled by an act of the Illinois General Assembly,[3] after the DeKalb County court intervened.

That year the county commissioners appointed three citizens, Ellzey P. Young, Kimball Dow, and J.C. Kellogg, to contract for a new courthouse building.

Eventually, William Phelps was contracted for the construction of the two-story brick structure which was topped with a large cupola clock tower.

[7] Haish eventually pledged $103,000 for a DeKalb courthouse but it was decided that the county seat would stay in Sycamore and ground was broken, despite the continuing legal battle, on October 29, 1903.

The building was completed on March 1, 1905 and the Crew Brothers Company was hired to demolish the 1850 DeKalb County Courthouse.

[4] In 2006 the United States Department of Justice announced it had arrested Derrick Shareef on terrorism related charges.

Among the crimes the government accused Shareef of plotting was a plan to assault the DeKalb County Courthouse in order to "smoke a judge.

Dewey was accused of murdering and burning the body of Susan Brady, who disappeared on December 20, 1965; he was arrested in for the crime in February 1966.

About 150 students blockaded the roads leading to the forested site with debris; twelve were arrested and the subsequent proceedings at the DeKalb County Courthouse were covered by the Chicago Tribune.

[13] During the summer of 1990 an exiting judge, Rex Meilinger, presented an unusual request to the DeKalb County Board.

Meilinger assured the board that the move was legal and preparations began for a catered dinner for more than 200 guests at the DeKalb County Courthouse.

The courthouse's setting, on the public square in downtown Sycamore, renders it an impressive structure from most approach angles.

[15] Heavily carved stone brackets support a lintel over the main doors on the building's front facades.

The four columns dominating the front extends two stories and blend Ionic and Corinthian elements as they ascend from the second floor to the cornice level of the courthouse.

[15] Classical sculpture covers the pediment above the front colonnade, with the seal of the State of Illinois dominating the relief.

[15] The north side of the DeKalb County Courthouse is not as ornately decorated as the south face but each has its own distinctive qualities.

The second floor landing offers a view of the stained glass windows, all original, which were fully restored during the 1980s renovation.

[14] Inside the ornate building's third-floor courtroom is a stained glass skylight centered by a ten-pointed star.