Frequent causes of just complaint have arisen upon the part of the citizens of the United States, some times from the irregular action of the constituted subordinate authorities of the maritime regions and some times from the leaders or partisans of those in arms against the established Governments. In all cases representations have been or will be made, and as soon as their political affairs are in a settled position it is expected that our friendly remonstrances will be followed by adequate redress. The Government of Mexico made known in December last the appointment of commissioners and a surveyor on its part to run, in conjunction with ours, the boundary line between its territories and the United States, and excused the delay for the reasons anticipated--the prevalence of civil war. The commissioners and surveyors not having met within the time stipulated by the treaty, a new arrangement became necessary, and our charge d'affaires was instructed in January, 1833 to negotiate in Mexico an article additional to the pre-existing treaty. This instruction was acknowledged, and no difficulty was apprehended in the accomplishment of that object. By information just received that additional article to the treaty will be obtained and transmitted to this country as soon as it can receive the ratification of the Mexican Congress. The reunion of the three States of New Grenada, Venezuela, and Equador, forming the Republic of Colombia, seems every day to become more improbable. The commissioners of the two first are understood to be now negotiating a just division of the obligations contracted by them when united under one government. The civil war in Equador, it is believed, has prevented even the appointment of a commissioner on its part. I propose at an early day to submit, in the proper form, the appointment of a diplomatic agent to Venezuela, the importance of the commerce of that country to the United States and the large claims of our citizens upon the Government arising before and since the division of Colombia rendering it, in my judgment, improper longer to delay this step. Our representatives to Central America, Peru, and Brazil are either at or on their way to their respective posts. From the Argentine Republic, from which a minister was expected to this Government, nothing further has been heard. Occasion has been taken on the departure of a new consul to Buenos Ayres to remind that Government that its long delayed minister, whose appointment had been made known to us, had not arrived.