History of the 151st field artillery, Rainbow Division, by Louis L. Collins, lieutenant governor of Minnesota. Edited by Wayne E. Stevens, PH. D. Pub. by the Minnesota War records commission.

EARLY HISTORY OF THE REGIMENT

9

The Minnesota artillery at Llano Grande could not move because
of the universal discrepancy between sizes of the horses' necks and the
sizes of the army steel collars. The collars did not fit and apparently
were not possible of an adjustment that would make them fit. The result was that extended mounted drill was impracticable and officers
of the battalion were trying to arrange to have the pieces dragged
to Brownsville behind motortrucks so that the men could get some
much needed firing practice. Palo Alto battlefield was the only place
in the valley where the army could secure a sufficient expanse of unpopulated land for artillery practice, and its flatness, absence of ridges
and rolling country made the test of up to date indirect firing out of the
question.5
A little later an opportunity presented itself for some much-needed
artillery practice at Point Isabel, Texas, a flat, sandy waste on the
Gulf of Mexico about sixty miles from Llano Grande. Batteries D and
E marched the distance in about three days.
For more than seven weary months the regiment played the nearwar game on the border, waiting in vain for some occurrence which
would bring the order to invade Mexico. Each day, with few exceptions, was like its predecessor - sand and heat in the daytime, with
comfortable nights; foot and gun drill, varied by occasional "hikes,"
inspections, and reviews. One of the marches was to Brownsville, near
the battlefield of Palo Alto, where General Zachary Taylor defeated
the Mexicans in 1846. Among the reviewing officers who visited the
regiment was Brigadier General James Parker, in command of the
Brownsville division - a man who was every inch a soldier.
The invasion of the bandit-infested region in northern Mexico by
the expeditionary force under General Pershing eventually brought
quiet to the border. After an encounter at Carrizal on June 21, 1916,
between a detachment of the 10th United States Cavalry and troops of
the de facto government, the American force was not seriously disturbed. The border was occasionally threatened by raids, but nothing
of a serious nature occurred. It was necessary, however, to maintain
a large force of regulars and national guardsmen there for some months
longer, although by the fall of 1916 the situation had cleared sufficiently to permit the withdrawal of a part of the latter.

5Minneapolis Journal, September 24, 1916.