Die Musterung des Regiments begann am 16. Mai 1861 in New Orleans/LA. 
In der Regel  bestand ein Regiment aus zehn Kompanien. 
Die 1st Texas hatte deren zwölf, die überwiegend aus südlichen  Counties (Landkreisen) kamen.

Company A  Marion Rifles           Marion County
Company B  Livingston Guards    Livingston County
Company C  Palmer Guards          Harrison County
Company D  Star Rifles                 Marion County
Company E  Marshall Guards       Harrison County
Company F  Woodville Rifles       Tyler County
Company G  Reagan Guards         Anderson County
Company H  Texas Guards           Anderson County
Company I  Crockett Southrons    Houston  County
Company K  Texas Invincible      San Augustine County
Company L  Lone Star Rifles       Galveston County
Company M  Sumter Light Infantry    Trinity County