The Athenians turned first to rebuilding the agora following the Persian War because it was the heart of their political and commercial activity. The agora was also the site of important religious and cultural events. By rebuilding the agora, the Athenians were able to restore their economic and political power, and demonstrate their resilience in the face of the Persian invasion. Additionally, the rebuilding of the agora provided an opportunity for the Athenians to showcase their artistic and architectural achievements, which helped to reinforce their cultural identity and prestige.