The Reasons for
Deserting and
Joining the Opposing
Army
Very few historians
have written about
the
San Patricios.
There are two
reasons for this, on
the American side
the war was
unpopular and was
ultimately over
shadowed by the
American Civil War.
Besides the debate
within the United
States about the
war, the high
desertion rates from
the American lines
made the discussion
of the war taboo
within the American
military.
On the Mexican side,
the loss of a
substantial part of
its territory and
the ongoing civil
strife within Mexico
has left a lack of
historical record
for the war. Two
authors have written
two books about the
Saint Patrick
soldiers. They are
Peter F. Stevens who
wrote “The Rogue’s
March: John Riley
and the St.
Patrick’s Battalion”
and Robert Ryal
Miller, author of
“Shamrock and Sword,
The Saint Patrick’s
Battalion.” Although
they both discuss
the high desertion
rate of the American
soldiers, they seem
to be trying to
minimize the actions
of the American Army
before the war
started.
Historians on both
sides of the border
have acknowledged
that the Americans
were intent on
instigating war with
Mexico through
unprovoked crimes;
such as rapes and
plunder and
especially the
desecration of
Catholic Churches in
Texas, the disputed
territory. Also,
many immigrants in
the American army
not only felt
discriminated upon
6 by
their fellow
soldiers but also
could not accept the
American provocation
for war. They began
to dissert and cross
the river to join
the Mexican army in
defense of Mexico.
From the moment of
the first battle at
Palo Alto on May 8,
many of the
deserters battled
their former
comrades.
German Christopher
Friedrich Wilhelm
Zeh, who
coincidently did not
like Mexicans, wrote
in his memoirs that
the US Army was a
multicultural group
where one of every
thousand was an
immigrant. 7
By his own
admission, Zeh was
an educated
immigrant who
considered himself
an aristocrat.
Although the
American Army was
composed of recent
immigrants,
discrimination
permeated through
the ranks. Catholic
prejudice 8
and harsh treatment
by Anglo-American
superiors and the
use of extreme
disciplinary
measures such as
flogging added to
the reasons for the
desertions from
Taylor’s ranks.9
“Potato heads” as
the Irish were
commonly called were
particularly singled
out for harsh
treatment. 10
Under these
conditions the
immigrants had no
difficulty
abandoning their
army and joining the
Mexican lines in
defense of Mexico.
Mexico was
especially active in
recruiting the
deserters.
