sentences:  On March 5, 1823, John Tumlinson Sr., the first alcalde of the Colorado district of the Old 300 of Stephen Fuller Austin's colony, is considered by many Texas Ranger historians to be the first Texas Ranger killed in the line of duty.He wrote to the Baron de Bastrop in San Antonio that he had "appointed but one officer who acts in the capacity of constable to summon witnesses and bring offenders to justice.