Short answers, pulled from the story.
The Apollo program needed a way to test its launch escape system without spending millions on full-scale rockets. Engineers at the Manned Spacecraft Center in Houston, Texas, faced a tight budget and a heavy schedule of high-priority launches elsewhere. They could not find an existing vehicle that offered both the necessary payload capability and thrust versatility for their planned tests.
White Sands Missile Range in New Mexico emerged as the best choice because it allowed land recovery instead of expensive water recovery. Launch Complex 36 at White Sands had previously been used for Redstone missile tests. This location met all schedule and support requirements while keeping costs low.
The Qualification Test Vehicle launched on the 28th of August 1963 carrying a dummy payload shaped like an aluminum shell. This test proved the rocket functioned correctly before the first abort attempt. A-001 occurred on the 13th of May 1964 using boilerplate BP-12 with a live launch escape system.
General Dynamics/Convair served as the prime contractor for the launch vehicle itself. North American Rockwell held the contract for the spacecraft portion of the operation. The Manned Spacecraft Center directed all activities from Houston, Texas.
Two major difficulties emerged during development that threatened the entire program schedule. The Qualification Test Vehicle failed to destruct when commanded because improperly installed primacord did not propagate detonation to shaped charges on the Algol motor case. The fourth mission vehicle became uncontrolled approximately 2.5 seconds after lift-off due to an electronic failure moving an aerodynamic fin hard over.