From 1891 to 1911, both the district and circuit courts were federal trial courts. The circuit court was abolished in 1911, and the district court became the sole federal trial court. Petitioners could file for writs of habeas corpus in either court, but they almost always filed their petitions in the district court.
I obtained data on both courts from two sources. From the courts' docket books, I recorded the disposition (as well as other basic information) for all the immigration and deportation cases filed during the period. From these cases, I drew a random sample (using a random number chart), choosing 10 percent or five cases, whichever was larger, from each year for an in-depth review of the case files. The files often contained the transcripts of the court hearings, which were the primary sources used, and the notes and transcripts from the agency's investigation. I adopted the same method in analyzing the deportation cases handled by the U.S. commissioner, who kept his own docket and case files.