The Avengers team considered going back in time to 2988 BC in Avengers: Endgame, which would put them at the center of a significant event involving an Infinity Stone. Marvel Studios was able to revisit several major moments from the Marvel Cinematic Universe thanks to Avengers: Endgame‘s time travel plot. The Battle of New York in 2012 from The Avengers, Star-Lord’s trip to Vormir in 2014 from Guardians of the Galaxy, and Thor’s time on Asgard in 2013 from Thor: The Dark World all served as essential parts to the Avengers’ plan.
The goal of the team was to travel back in time using the Quantum Realm and take the Infinity Stones so they can reverse Thanos’ snap in the present. While three time periods and four teams were ultimately what were chosen, the Avengers (and the film’s creators) considered many other options. One of them was going back to 2009, but another one of their alternate plans appeared to include going thousands of years in the past.