Claim: Is King Charles the first British monarch to address the US Congress?

The claim that King Charles is the first British monarch to address the US Congress is mostly false. Reports indicate that he will be the second British monarch to do so, following Queen Elizabeth II's address in 1991. Mainstream sources like Fox News and Time confirm this historical context. However, there are no opposing sources disputing this specific claim, which strengthens the consensus around its accuracy. The models diverge sharply — treat this as higher-uncertainty. Gemini comes in highest (50%), while Perplexity is lowest (0%). Perplexity expresses higher confidence than Gemini on this claim. While the evidence strongly supports that King Charles is not the first British monarch to address Congress, the absence of contradicting sources leaves some room for uncertainty. If new information were to emerge suggesting a different interpretation of historical events or additional context, it could potentially alter the understanding of this claim. However, based on the current evidence, the assertion remains that he follows Queen Elizabeth II in this regard.