No better proof of the good faith of the United States could have been given, than the vigor with which we have acted, and the expense incurred, in suppressing the enterprise meditated lately by Burr against Mexico. Although at first, he proposed a separation of the western country, and on that ground received encouragement and aid from Yrujo, according to the usual spirit of his government towards us, yet he very early saw that the fidelity of the western country was not to be shaken, and turned himself wholly towards Mexico. And so popular is an enterprise on that country in this, that we had only to lie still, and he would have had followers enough to have been in the city of Mexico in six weeks. You have doubtless seen my several messages to Congress, which give a faithful narrative of that conspiracy. Burr himself, after being disarmed by our endeavors of all his followers, escaped from the custody of the court of Mississippi, but was taken near Fort Stoddart, making his way to Mobile, by some country people, who brought him on as a prisoner to Richmond, where he is now under a course for trial. Hitherto we have believed our law to be, that suspicion on probable grounds was sufficient cause to commit a person for trial, allowing time to collect witnesses till the trial. But the judges here have decided, that conclusive evidence of guilt must be ready in the moment of arrest, or they will discharge the malefactor. If this is still insisted on, Burr will be discharged; because his crimes having been sown from Maine, through the whole line of the western waters, to New Orleans, we cannot bring the witnesses here under four months. The fact is, that the federalists make Burr's cause their own, and exert their whole influence to shield him from punishment, as they did the adherents of Miranda. And it is unfortunate that federalism is still predominant in our judiciary department, which is consequently in opposition to the legislative and executive branches, and is able to baffle their measures often. Accept my friendly salutations, and assurances of great esteem and respect. TO WILLIAM B. GILES. MONTICELLO, April 20, 1807.