BadNick

You're right about her speed and the US gov't funding, as well as the advanced design. This is a pretty good summary of those points:

From wikipedia:
"...Designed by renowned American naval architect and marine engineer William Francis Gibbs, the liner's construction was a joint effort between the United States Navy and United States Lines. The U.S. government underwrote $50 million of the $78 million construction cost, with the ship's operators, United States Lines, contributing the remaining $28 million. In exchange, she was designed to be easily converted into a troopship or a hospital ship in the case of war.

She was built from 1950-1952 at the Newport News Shipbuilding and Drydock Company in Newport News, Virginia. Her keel was laid and her hull was constructed in a graving dock. The United States was built to exacting Navy specifications, which required that she be heavily compartmentalized and have separate engine rooms to enable her to survive should she be damaged in war.

Mindful that during World War II U.S. aircraft carriers, with wooden flight decks, tended to catch fire more readily than steel-decked British carriers, the designers of the United States did not use a single piece of wood in her framing, accessories or decorations. There were no wood interior surfaces. Fittings, including all furniture and fabrics, were custom made in glass, metal and spun glass fiber to ensure they were in full compliance with strict fireproof guidelines set by the U.S. Navy. Even the clothes hangers in the luxury cabins were made of aluminum. The only wooden equipment used in the construction of the vessel was in the bilge keels and butcher blocks in the galleys. The grand piano in the ballroom was even made of a rare, fire-resistant species of wood.

The construction of the ship's superstructure involved the largest use of aluminum in any construction project to that time, and presented a special challenge to the builders in joining the aluminum structure to the steel decks below. The significant use of aluminum provided an extreme weight savings. At 106 feet (32 m) beam, the United States was built to Panamax capacity, ensuring that she could clear the Panama Canal locks with just 2 feet (0.6 m) to spare on either side. The United States featured the most powerful engine installation in a merchant marine vessel and the most powerful in any vessel, civilian or naval, apart from later U.S. supercarriers. She was capable of steaming astern at over 20 knots (37 km/h) and could carry enough fuel and stores to steam non-stop for over 10,000 nautical miles (18,520 km).

Embarking on her maiden voyage on 4 July 1952, the United States smashed the transatlantic speed record held by the Queen Mary for the previous 14 years by over 10 hours, making her maiden crossing from the Ambrose lightship at New York Harbor to Bishop Rock off Cornwall, UK in 3 days, 10 hours, 40 minutes at an average speed of 35.59 knots (40.96 mi/h). The liner also broke the westbound crossing record by returning to America in 3 days 12 hours and 12 minutes at an average speed of 34.51 knots (39.71 mi/h), thereby obtaining both the eastbound and westbound Blue Ribands. The United States maintained a 30 knot (56 km/h) crossing speed on the North Atlantic in a service career that lasted 17 years. During her career her Captains were Harry Manning, John Anderson and Leroy J. Alexanderson. She was very popular and proved to be a worthy competitor to the Cunard Line's Queen Mary and Queen Elizabeth.

The maximum speed of the United States was deliberately exaggerated, and kept obscure for many years. An impossible value of 43 knots (80 km/h) was leaked to reporters by engineers after the first speed trial. The actual top speed — 38.3 knots (44.1 mi/h) — was not revealed until 1977..."