To the amazement of practically everybody except Bailey, the dam complex
was working. By May 6, the water held by the dam had risen 4 feet. By
May 8, the water level was up 5 feet 4 inches. Three of the lighter
vessels even crossed the upper rapids and now waited behind the dam for
the heavier gunboats. As the soldiers worked to finish the dam, the
water continued to build until the pressure against the dam became
tremendous. General Banks feared the pressure would soon burst the dam,
and the next day, at around 5:30 in the morning, one officer “heard a
great crashing in the direction of the dam. Jumping out of the blankets
and slipping on my coat, cap, and boots, I ran down to the bank. The
water was rushing through at a great rate” (Tyson May 9, 1864).
Two of the barges used in the dam had broken loose, and the water was
gushing through. Porter, seeing the crisis, quickly ordered the gunboat
_Lexington_ to run the gap:
[Illustration: Porter’s fleet passing through Colonel Bailey’s Dam
above Alexandria, May 1864. From _Frank Leslie’s Illustrated
Newspaper_, July 16, 1864. Courtesy of the Library of Congress.]
The Lexington succeeded in getting over the falls and then steered
directly for the opening in the dam, through which the water was
dashing so furiously that it seemed as if certain destruction would be
her fate. Ten thousand spectators breathlessly awaited the result. She
entered the gap with a full head of steam; passed down the roaring,
rushing torrent; made several spasmodic rolls; hung for a moment, with
a harsh, grating sound, on the rocks below; was then swept into deep
water, and rounded to by the bank of the river. Such a cheer arose
from that vast multitude of sailors and soldiers, when the noble
vessel was seen in safety below the falls, as we had never heard
before, and certainly have not heard since (Moore 1868:12).
The _Lexington_’s run was followed by the three gunboats waiting behind
the dam. Had the rest of the fleet been prepared, all of the boats might
have escaped at that time. However, the navy’s lack of confidence in the
dam had given way to apathy, and as the released water rushed through
the break, valuable time was wasted as the fleet gathered steam to
attempt the run. Eventually, the water behind the dam fell and six
gunboats still remained trapped.
But the _Lexington_’s adventure had proven that the dam could work, and
troops confidently went back to work. Bailey worried that the dam would
break again and decided to leave the 70-foot gap in the dam as it was.
But this time he added smaller, lighter dams near the upper rapids. Like
the dam sections at the lower rapids, both crib and tree dam methods
were employed. These dams helped channel the water while reducing the
pressure on the main dam. Thus, instead of relying on one dam to hold
back the water until another run could be made, a series of dams were
built to create a deep channel of water along the whole course of the
shoals in that part of the Red River.
Unfortunately, during Coastal Environments’s archaeological excavations,
this dam complex at the upper rapids was believed to be destroyed by
modern development. Later, the U.S. Army Corps of Engineers conducted an
underwater survey, locating what clearly appear to be parts of these
upper works. If so, these submerged dam sections are preserved so that
perhaps someday archaeologists may have an opportunity to investigate
more of Bailey’s engineering feat.
While the army labored to build the upper dam, the navy, more confident
of rescue, worked to lighten the loads on the trapped gunboats. From May
10 through 12, the remaining gunboats above the rapids struggled through
the upper shoals to the pool behind the main dam. Yet another dam had to
be built to refloat a gunboat that got stuck during this passage. Then
on the twelfth of May, the _Mound City_, the largest gunboat of the
fleet, ran for the gap in the main dam. The previous scene was repeated,
with thousands lining the banks to watch the excitement. Marching bands
played the “Star Spangled Banner” and the “Battle Cry for Freedom.” Like
the _Lexington_ before it, as the _Mound City_ hit the gap, it ground
against the rocky river bottom, and then shot through. The next day all
of the trapped vessels lay safely below the rapids.