The best solid wood floor in the United States, particularly among oak species, is typically the White Oak. This is due to its hardness, durability, and aesthetic appeal. White Oak is harder than Red Oak, which makes it more resistant to wear and tear, especially in high-traffic areas. According to the American Hardwood Export Council, White Oak has a Janka hardness rating of 1360, compared to Red Oak's 1290. This higher rating indicates that White Oak is more durable and less prone to dents and scratches.

The data from the Janka hardness test is a crucial factor in determining the longevity of a solid wood floor. The Janka hardness scale measures the force required to embed a .444-inch steel ball to half its diameter into the wood. A higher score means the wood is harder and more resistant to damage. White Oak's superior hardness makes it an excellent choice for homes with pets, children, or heavy furniture. Additionally, White Oak has a more open grain pattern, which allows for a more rustic and natural look, enhancing the overall aesthetic of the space.

Furthermore, White Oak is versatile in terms of finishes and stains. Its light color and subtle grain patterns can be easily customized to match various design preferences, from traditional to modern. This adaptability makes it a popular choice among homeowners and interior designers alike. In contrast, Red Oak, while still a durable option, may not hold up as well over time due to its softer nature.

In summary, the White Oak solid wood floor is the better choice due to its higher hardness, durability, and aesthetic versatility. The Janka hardness rating and the wood's open grain pattern contribute to its superior performance and appeal in the United States market.