The Apollo spacecraft was a collaborative effort of several companies and organizations, but the primary contractor for the spacecraft's development and construction was North American Aviation (later known as Rockwell International).

Here's a breakdown:

* North American Aviation: Designed and built the Command and Service Modules (CSM), which housed the crew and provided life support, propulsion, and other systems.

* Grumman: Designed and built the Lunar Module (LM), which landed on the Moon and returned the astronauts to the CSM.

* Boeing: Developed and manufactured the Saturn V rocket, which launched the Apollo spacecraft to the Moon.

* Other companies: Numerous other companies contributed components and systems for the Apollo spacecraft, including TRW, IBM, and General Electric.

* NASA: Of course, NASA was the overall project manager and responsible for the program's direction and oversight.

It's important to remember that the Apollo program was a massive undertaking involving thousands of engineers, scientists, technicians, and other professionals. The successful completion of the program was a testament to the collaborative efforts of numerous companies and organizations.