What was the first photo ever posted on Instagram?

The first photo ever posted on Instagram was shared by co-founder Kevin Systrom on July 16, 2010, before the app was publicly available. The photo features a stray dog and a sunset, and it was taken at a taco stand in Mexico. Systrom shared the photo as a test to see if the app's functionality was working correctly.

The photo, which was posted under the username "kevin", was captioned "Test" and included the hashtags "#testing" and "#dog". It received its first like from co-founder Mike Krieger. The original photo was taken down when Instagram was officially launched, but it has been recreated and shared by Systrom on various occasions.

The first photo posted on Instagram after its public launch was shared by Systrom on October 6, 2010, the day the app became available in the App Store. The photo, taken at a farmer's market in San Francisco, features a beautifully arranged stand of fruits and vegetables. This photo marked the beginning of Instagram's journey as a popular photo-sharing platform.