[1] The majority opinion reversed Beach's conviction, even bringing up transcripts of congressional debate on whether the Mann Act applied to the District of Columbia.

Justice Edgerton's dissent had the following arguments,"The court makes a case for the proposition that the inclusion of the District of Columbia in the Mann Act is unfortunate, but that is not the question.

[3] The Court states that the historical evidence had it believe that,"[Congress] specifically and repeatedly includes in its prohibition, such transportation "in any Territory or in the District of Columbia."

Congress, in enacting the Mann Act, made it perfectly plain by its Committee Reports on the proposed legislation that it was intended to apply to transportation taking place wholly within the District of Columbia."

The decision rejected the argument that the law would be unnecessary, stating, "[w]hether the District was already adequately protected from the evils of prostitution without the added prohibition of transportation for that purpose was for Congress, not the courts, to decide.