Oh...this will be interesting. I hope you all did your research into what post Civil War Laredo was like. It was not a large city, the area was kept under law by the recently returned Union army and those it recruited into helping, mostly ex Rangers and lawmen. There probably would not be a sheriff or deputies or any of that. Reconstruction government was ruling at the time, cattle drives were a big money maker for the ranches nearby and there was plenty of cattle rustling and banditry across the border. Also, a note, there is Nuevo Laredo right across the Rio Grande which is where most of the native born ethnic Mexican population went after the Treaty of Guadalupe Hildalgo ignored Laredo's vote to stay part of Mexico.
GM, what season is it? Laredo has two seasons, scorching hot and mildly warm.
Just did some reading, the county's population went from about 1,400 people in 1860 to 2,615 by 1870. So all those newcomers had to come from somewhere, some carpetbaggers and some trying to start a new life away from the war's devastation.