Boston allowed private groups to hold ceremonies at City Hall Plaza and temporarily raise flags of their choosing on a third flagpole. After approving hundreds of ceremonies, the city denied a request from a Christian organization to raise its flag because officials feared that doing so would amount to government endorsement of religion. The Supreme Court held that Boston had created a public forum for private expression and could not deny the request based on the flag’s religious character. The city had not consistently controlled the messages conveyed by the third flagpole, and its policy lacked clear, objective limits distinguishing government speech from private speech. The Court therefore reversed the First Circuit and held that Boston violated the organization’s First Amendment rights. The judgment was unanimous.