First becoming popular during the Renaissance, Neoclassical architecture remained popular well into the 20th century and is still recognizable on a number of prominent structures today.

Designed to reflect the appearance of Greek and Roman buildings, Neoclassical architecture sought to promote the simpler beauty of these structures. George D. Hopkins Jr., author of the 2009 book "Creating Your Architectural Style," says the style came to be a response to the more ostentatious features of Rococo architecture. The designs of Italian architect Andreo Palladio started the style on its way to widespread popularity.

Neoclassical architecture in the United States became particularly popular after the War of 1812, with the designs aiming to pay tribute to the principles of Greek democracy and reassert American independence. Ironically, designers often found their ideas for ornamentation in British pattern books.

Symmetry is one of the main characteristics of Neoclassical architecture. Douglass Trattner, writing for HGTV, says the style typically incorporates the "golden ratio" in its proportions.

The front of a Neoclassical structure is defined by a porch with an even number of columns reaching up to the roofline. These columns support a triangular pediment.

Doorways usually have decorative elements, including their own pediment. Windows typically have even spacing, six or eight panels, and shutters.

The Neoclassical style was often used for monumental public buildings, such as the U.S. Capitol, White House, and Lincoln Memorial. Domed roofs are a common feature.

However, the Neoclassical style also became a popular style for private residences. One of the more famous examples is Thomas Jefferson's estate of Monticello.

The style came to influence other types of architecture over the years, including Greek Revival and Beaux Arts. The Louisiana Office of Cultural Development says Neoclassical buildings tend to feature wide expanses of plain walls, but also have more detail in decorated elements such as the pediments. Hopkins says the most detailed areas of these structures tend to be on the roof edges, corners, cornices, and molding.

Neoclassical structures come in a variety of building materials and layouts. Public buildings often have a T- or U-shaped layout. This versatility made the style adaptable to buildings of all sizes.

Victorian architecture became more popular in the 19th century, causing a brief downturn in Neoclassical buildings. However, the style reemerged as a counter to the more ornate features of Victorian buildings.