Designed by Fort Worth architect Wyatt C. Hedrick, the eighteen-story building with a green tile pitched roof and 1,100 rooms was conceived by McCarthy as a city-sized hotel scaled for conventions with a resort atmosphere.

[1][3] Politician and entrepreneur Jesse H. Jones privately warned McCarthy that business travelers would be reluctant to stay at a hotel three miles south from downtown Houston.

[10] The party was attended by over 150 Hollywood celebrities including Ginger Rogers, Hedda Hopper, Robert Preston and Errol Flynn along with noted Los Angeles business executives and reporters, some of whom were flown in to Houston International Airport on a customized Boeing 307 Stratoliner airplane which McCarthy had bought only days earlier from Howard Hughes.

With a crowd estimated at 50,000 gathering outside the hotel, newspaper boys dressed in black tie handed out commemorative editions of the Houston Post as guests arrived that evening.

[12] The festivities became so raucous that a radio broadcast from the hotel by actress, singer and World War II pinup girl Dorothy Lamour was cut off by the network; assuming he was off-air, NBC audio engineer Raoul Murphy uttered an expletive heard live nationwide and dead air greeted the audience for a very long twenty seconds.

Guests signed the register in "grass-hued" green ink and their luggage was carried by bellhops wearing emerald green, lemon trimmed uniforms past a portrait of McCarthy in the elevator lobby to air-conditioned, green-hued rooms each with generously framed abstract art on the walls, push-button radios (including recorded music from an elaborate in-house system through which an operator played extended-length phonographic records) and television, all somewhat rare amenities for a hotel at the time.

McCarthy had spent lavishly, then borrowed heavily against his assets (including the hotel) to leverage a series of risky investments and his cash reserves quickly dwindled.

[18] Despite financial troubles the resort-like Shamrock with its restaurants, bars and swank shops had become a popular gathering place for local society and was characterized as "Houston's Riviera" during the early 1950s.

The Shamrock's private and sleek Cork Club was noted as the site of many oil deals (and reportedly, fist fights), along with performances by singer Frank Sinatra.

Meanwhile, affluent suburban home buyers bypassed the area and the planned shopping and entertainment center was never built (although McCarthy's concept influenced the successful Houston Galleria which opened near an intersection of freeways on the city's west side in 1970).

[20] The hotel remained popular for Houston social events such as debutante balls, barbecues and business meetings, continuing operations as the Shamrock Hilton until 1986, by which time even its local reputation had long since faded.

During a severe local recession in 1985, the 36-year-old hotel, still the second largest in Houston but by then in need of extensive refurbishing and refitting, was in effect donated to the Texas Medical Center.

The Albert B. Alkek Institute of Biosciences and Technology Building, a component of the Texas A&M Health Science Center, was constructed on the former north gardens of the hotel in 1992.