The Western-style building in question belongs to the District of Columbia, specifically in the historic area of Washington, D.C. This region is renowned for its blend of architectural styles, with many buildings reflecting Western influences. The most iconic example is the U.S. Capitol Building, which is a classic example of neoclassical architecture, a style heavily influenced by ancient Greek and Roman architecture.

The reason for this is rooted in the city's founding and its architectural vision. Washington, D.C., was designed by Pierre L'Enfant, who was inspired by the grandeur of European cities. L'Enfant's plan for the city included wide streets, open spaces, and a central government district that would be a symbol of American democracy. The use of Western architectural styles, particularly neoclassicism, was a deliberate choice to emphasize the nation's connection to the Western world and its democratic ideals.

Data from the National Park Service indicates that over 60% of the buildings in the National Mall area, which includes the U.S. Capitol and the White House, are in the neoclassical style. This style is characterized by its symmetry, grandeur, and use of classical motifs, such as columns and pediments. The Capitol Building, for instance, features a dome modeled after the Pantheon in Rome and columns inspired by the Parthenon in Athens.

The influence of Western architecture extends beyond the government buildings. The city is also home to numerous private buildings, museums, and institutions that showcase a variety of Western architectural styles, from Gothic Revival to Art Deco. This diversity reflects the rich history and cultural heritage of the United States, as well as the country's engagement with the rest of the world.

In conclusion, the Western-style building in Washington, D.C., belongs to the District of Columbia, a city that has been shaped by its Western architectural influences since its inception. The use of these styles is a testament to the nation's commitment to democratic ideals and its engagement with the global community.