By 1890 the forty-year-old Greek Revival Hillsdale County Courthouse was aged and cramped for space and in 1898 the county's voters approved the expenditure of $45,000 for a new courthouse. This Georgian Revival design by Allen of Jackson uses locally quarried, light yellow-brown sandstone from the Marshall formation. The design of the building derives from William Chambers's Somerset House in London, England. With its arcaded porch supporting a balustraded, Composite order portico; a tall three-stage, domed central clock tower with a cupola; a copper-tiled roof; and an interior rotunda finished in paneled oak, it seemed everything a courthouse should be. The plan followed the cross-axis model, in which each of the four county offices occupies space off a rotunda in one of the four corners of the building. David Gibbs established the model for this plan in Ohio and in courthouses for Eaton and Ionia counties in Michigan in the 1880s. As supervisor of construction for the Ionia County Courthouse in 1884–1885, Allen was intimately familiar with this arrangement. In 1903–1904, two years after the Hillsdale County Courthouse was completed, Allen virtually duplicated it in the Van Buren County Courthouse at Paw Paw. Human and lion faces are carved in the foliated capitals of the square piers of the arcade.