The Brazilian II Corps was originally organized from various detachments in the Corrientes area. Thus it contained a number of "Provisional Corps", battalion sized units made up of detachments from other units. The II Corps was nicknamed "The Boys in Black Hats" due to the large number of troops from Brazil's southern provinces who tended to wear the broad brimmed black Gaucho hat in place of the kepi or barracks cap.

1st Division:

1st Brigade:

2nd Brigade:
1st Prov National Guard Cavalry
6th Prov National Guard Cavalry
2nd Prov National Guard Cavalry
7th Prov National Guard Cavalry
3rd Prov National Guard Cavalry
8th Prov National Guard Cavalry
4th Prov National Guard Cavalry
9th Prov National Guard Cavalry
5th Prov National Guard Cavalry

2nd Division:

3rd Brigade:
2nd National Guard Battalion
8th Volunteer Battalion
29th Volunteer Battalion
34th Volunteer Battalion

4th Brigade:
18th Volunteer Corps
32nd Volunteer Corps
35th Volunteer Corps
36th Volunteer Corps

5th Brigade:
5th Volunteer Corps
11th Provisional Line Battalion (Corps of Zouaves)

3rd Division:

6th Brigade:
10th Prov Infantry Corps
11th Prov Infantry Corps
12th Prov Infantry Corps
13th Prov Infantry Corps
14th Prov Infantry Corps

7th Brigade:
15th Prov Infantry Corps
16th Prov Infantry Corps
17th Prov Infantry Corps
18th Prov Infantry Corps
19th Prov Infantry Corps

Light Division:

8th Brigade:
20th Prov Infantry Corps
21st Prov Infantry Corps

9th Brigade:
22nd Prov Infantry Corps
23rd Prov Infantry Corps

Independant Infantry Brigades:

10th Brigade:
3rd Line Battalion
24th Prov Infantry Corps
25th Prov Infantry Corps
26th Prov Infantry Corps

11th Brigade:
27th Prov Infantry Corps
28th Prov Infantry Corps
29th Prov Infantry Corps
30th Prov Infantry Corps
1st Volunteer Troop
1st National Guard Reserve Coy
1st National Guard Reserve Corps

Corps Troops:

Information furnished by the Office of the Brazilian Military Attache, Washington, DC, USA