The question of the oldest restaurant still serving customers in a country raises interesting insights into the nation's culinary and cultural history. Different countries claim ownership to some of the oldest continuously operating dining establishments in the world. In the case of this question, the two answers provided point to two distinct nations: the United States and South Korea. Hereafter is an exploration into both the White Horse Tavern and Imun Seolleongtang, detailing their historical and cultural significance.

### White Horse Tavern (Newport, Rhode Island, United States)

#### Historical Background
White Horse Tavern, located in Newport, Rhode Island, was established in 1673 and holds the distinction of being the oldest tavern still in operation in the United States. Steel beams inscribed with "circa 1652" suggest that the building's construction dates back to the early colonial times, making it a site of historical significance as well.

#### Architectural Significance
The building's architecture is a classic example of early American colonial style, with massive beams, small leaded windows, and a clapboard exterior. Over the centuries, the tavern has been meticulously preserved, offering a window into the 17th century colonial American life.

#### Role in American History
Throughout its history, White Horse Tavern acted as a meeting place for colonial legislators, a boarding house, and a private residence before being restored in the 1950s to serve as a tavern and restaurant. It has been a central hub in Newport’s social and political life, hosting everything from colonial town meetings to gatherings of the local council.

### Imun Seolleongtang (Seoul, South Korea)

#### Historical Background
Imun Seolleongtang, founded in 1904, is located in Seoul, South Korea. It is the oldest restaurant in South Korea still in operation, famous for its seolleongtang, a traditional Korean ox bone soup.

#### Culinary Significance
Seolleongtang is a milky broth made by boiling beef bones for several hours until the soup becomes rich and creamy. This dish is highly nutritious and is hailed as a comfort food in Korean cuisine. Imun Seolleongtang was the first restaurant in Korea to use a pressure cooker to make seolleongtang, significantly reducing the cooking time and maintaining a consistent quality.

#### Socio-Cultural Role
Imun Seolleongtang was registered as "Tangible Cultural Property No. 36" by the Seoul Metropolitan Government. This designation highlights the restaurant's importance in the preservation and continuation of traditional Korean culinary practices. For over a century, this establishment has remained a place where patrons from diverse backgrounds gather to enjoy a traditional meal, reflecting the enduring culinary heritage of Korea.

### Comparison and Cultural Importance
The White Horse Tavern and Imun Seolleongtang, each holding the title of the oldest restaurant in their respective countries, serve as not only places to dine but as living museums that encapsulate centuries of socio-cultural evolution. Both establishments highlight the importance of preserving culinary traditions and historical architecture, offering locals and tourists alike a direct link to their country's past.

In summary, understanding the historical contexts and the impact of such establishments on their respective societies provides a greater appreciation for their roles not just as businesses, but as cultural institutions. Whether in the bustling historic district of Newport or the vibrant cityscape of Seoul, these restaurants offer a unique glimpse into the culinary and cultural practices that have shaped and defined nations over centuries.