The object of the application to the circuit court was to compel the Postmaster-General to carry into effect an award made by the Solicitor of the Treasury, under a special act of Congress for the settlement of certain claims of the relators on the Post-Office Department, which award the Postmaster-General declined to execute in full until he should receive further legislative direction on the subject.  If the duty imposed on the Postmaster-General by that law was to be regarded as one of an official nature, belonging to his office as a branch of the executive, then it is obvious that the constitutional competency of the judiciary to direct and control him in its discharge was necessarily drawn in question; and if the duty so imposed on the Postmaster-General was to be considered as merely ministerial, and not executive, it yet remained to be shown that the circuit court of this District had authority to interfere by mandamus, such a power having never before been asserted or claimed by that court.  With a view to the settlement of these important questions, the judgment of the circuit court was carried by a writ of error to the Supreme Court of the United States.  In the opinion of that tribunal the duty imposed on the Postmaster-General was not an official executive duty, but one of a merely ministerial nature.  The grave constitutional questions which had been discussed were therefore excluded from the decision of the case, the court, indeed, expressly admitting that with powers and duties properly belonging to the executive no other department can interfere by the writ of mandamus; and the question therefore resolved itself into this:  Has Congress conferred upon the circuit court of this District the power to issue such a writ to an officer of the General Government commanding him to perform a ministerial act?  A majority of the court have decided that it has, but have founded their decision upon a process of reasoning which in my judgment renders further legislative provision indispensable to the public interests and the equal administration of justice.

It has long since been decided by the Supreme Court that neither that tribunal nor the circuit courts of the United States, held within the respective States, possess the power in question; but it is now held that this power, denied to both of these high tribunals (to the former by the Constitution and to the latter by Congress), has been by its legislation vested in the circuit court of this District.  No such direct grant of power to the circuit court of this District is claimed, but it has been held to result by necessary implication from several sections of the law establishing the court.  One of these sections declares that the laws of Maryland, as they existed at the time of the cession, should be in force in that part of the District ceded by that State, and by this provision the common law in civil and criminal cases, as it prevailed in Maryland in 1801, was established in that part of the District.