What operating system version did the first iPad ship with?

The first iPad shipped with iPhone OS 3.2.

Apple released the original iPad in 2010, and it launched with iPhone OS 3.2 rather than the later iOS branding. This version was developed specifically for the iPad's larger screen and introduced tablet-oriented interface changes while retaining the operating system family used by the iPhone and iPod touch.

The first-generation iPad was announced by Steve Jobs on January 27, 2010. It featured a 9.7-inch LED-backlit IPS display, Apple's A4 chip, and storage options of 16, 32, or 64 GB. Unlike the iPhone 4 released that same year, the original iPad did not include a camera.

Apple later unified the platform's naming under iOS. The iPad received iOS 4.2.1 in November 2010, bringing features such as multitasking and folders. That later version can cause confusion when people remember iOS rather than the original launch software. iPhone OS 3.0 and 3.2 were also separate releases: version 3.2 was the iPad-specific starting point, while iPhone OS 3.0 belonged to earlier iPhone-era software.