Historic California Posts, Camps,
Stations and Airfields
The Citadel of Alcatraz
by Gordon Chappell
Regional Historian, Pacific West
National Park Service
The Post of Alcatraz
in 1908, just before the Citadel was razed. The Citadel is the
building on the top of the island. (Photograph courtesy of the
Alcatraz Island in San Francisco Bay is
famous as a United States Penitentiary for a period of roughly
thirty years--1933 to 1963. Yet it was an army post for eighty
years, first a heavy artillery coast defense installation guarding
the strait into San Francisco Bay, then as its defense importance
waned, increasing in importance as a military prison. In fact
it was the Army, not the Department of Justice, that built the
prison buildings later so famous as the home of Al "Scarface"
Capone and other notorious criminals.
Frequently described as "America's
Devil's Island" while a prison, Alcatraz was equally unique
as "America's Gibraltar," a nearly impregnable fortress
in its early days. Furthermore, as a fortification Alcatraz was
unique in its design. There were forts in the harbors of Boston,
New York, Charleston, Pensacola, and elsewhere in America, but
none even remotely approached Alcatraz in the form of the fortifications,
its strategic location in the harbor it protected, or in its
topography. Most such forts were on low-lying islands, not high
above the water. But Alcatraz, a steep, rocky mass reaching high
above the bay, was unique as a platform for fortifications.
The key element in the fortifications
of what the Army spelled variously as Alcatrazes, Alcatras, Alcatrasas,
Alcatrace, Alcatrose, Alcatrazas, Alcatrazos, Alcatrases, and
Alcatraz, and termed officially the "Post of Alcatraz Island"
and, on rare occasions, "Fort Alcatraz" was a number
of barbette batteries constructed in the rock with brick and
stone breast height walls, located mostly around the southwestern
side of the island commanding the Golden Gate, whose inner entrance,
roughly two and a half miles west at Point Cavallo, was just
barely within the two and a half mile reach of Alcatraz guns.
The only access to the island, which featured
steep cliffs around most of its shore, was from a pier on the
northeast side commanded by a brick and stone casemate featuring
11 cannon embrasures. From the pier, the only access to the heights
of the island-and except for the pier area the island was almost
all heights-was up a narrow road through sally port guarded by
infantry rifles and three flank howitzer embrasures. On the slopes
near the top were officers' quarters, the lighthouse, storehouses,
and many other frame structures, but the crowning fortification,
on the island's summit, was 'The Citadel,' a massive, fortified
Just as Alcatraz was unique as an island
fortress in America, the 'Citadel' on Alcatraz probably was unique
as a building in terms of its military architecture (though no
comprehensive study of American military architecture has been
done which can prove that point.) It was built of the material
typical of seacoast fortifications mounting heavy artillery-brick
and stone; it was enclosed by a moat as were many such forts--in
this instance a dry moat. Its basic plan was more like that of
a palisaded frontier fort, a rectangle with bastions equivalent
to blockhouses at two diagonal corners to provide flanking fire
along the four walls. But this Citadel, this fortified barracks,
was designed to be, defended solely by rifle fire--it did not
have a single cannon embrasure, and this is what made it so unusual
and possibly unique.
The Alcatraz Citadel had three stories.
The first or basement level was sunk below ground level and was
surrounded by a dry moat which the army termed a "ditch."
This is the only portion of the Citadel which survives. The second
level or first story was at ground level, and had access over
drawbridges at each end across the dry moat. The basement had
rifle embrasures all the way around, the second level had narrow
windows which could double as rifle embrasures, and the third
level or second story had still slightly wider windows which
also could double as rifle embrasures, while the roof provided
a forth story of protection, for it was surrounded with a parapet
over which infantry could fire at an enemy. The rifle embrasures
and windows all were protected by iron shutters which could be
closed against hostile fire.
Plans for the Citadel were prepared by
2nd Lieutenant Frederic E. Prime in June 1857 (The first guns
on Alcatraz had already arrived and been mounted in the South
Battery in 1853.) The Citadel basement was to contain four officers'
kitchens, four officers' bedrooms. an officers' storeroom, the
company kitchen, a bakery, four storerooms in the enlisted men
s section, and a prison room adjoined by one light and one dark
cell. The first floor had four officers' dining rooms, four parlors,
one servant's room, one company mess room, one reading room for
enlisted men, one company office, two sergeants' rooms, one laundresses'
kitchen., and two laundresses' bedrooms. The top floor was divided
into eight officers' bedrooms, one servant's room, two enlisted
men's dormitories or barracks, and two more sergeants' rooms.
Built into the counterscarp around the dry moat at the basement
level were eight small storage rooms for vegetables, coal, and
the like, and a privy for enlisted men. By June 1858 the excavation
for the building and its moat were completed, and its brick walls
were going up. It was finished by the end of November 1859.
The guns on Alcatraz never fired a shot
in anger, and neither did the Citadel. That they never did may
have been a mark of their success as a deterrent to enemy attack
on San Francisco Bay, for during the Civil War the Confederate
raider Shenandoah did attack the Union commercial whaling fleet
in North Pacific waters, and without the deterrent of strong
defense of the Golden Gate, that ship could easily have slipped
into the Bay to shell the city and perhaps capture Mother Lode
gold held in its banks, diverting it to finance the failing Confederacy.
After the war, the importance of Alcatraz as a fort waned as
larger and longer range guns were developed, and as defense batteries
correspondingly progressively farther west toward the seaward
approaches. In 1882, the Citadel was converted into six sets
of officers' quarters and served thereafter as a sort of officers
The importance of Alcatraz as a prison
grew and when plans were drawn up for the first truly permanent
military prison building, it was to be located at the summit
of the island in place of the Citadel. Late in 1908 demolition
of the upper two stories of the old Citadel began; the basement
level and dry moat were to remain as foundations and basement
for the new prison. Major Reuben B. Turner, the commandant and
construction quartermaster, also used the two old granite entrances
to the Citadel as entrances in the new prison, and salvaged an
ornate iron stairway similar to those at Fort Point to run from
the hallway between the cell block and mess hall down to the
lavatory. Thus roughly a third of the old Citadel survives, which
has led over the years to rumors of mythical Spanish dungeons
beneath the penitentiary. And to the extent that the basement
level of the old Citadel once contained a prison room and two
cells, there was perhaps a grain of truth even to that old wives'
The Citadel, circa
1869 (Photgraph courtesy of John Martini)
The Citadel circa
1893 (Photograph courtesy of John Martini)
with the Citadel in the background (Photograph courtesy of the
Originally Published in 1981
for the annual meeting of the Council on Abandoned Military Posts.
Reprinted with permission of the author