On this day, the right wing of the 16th Ohio was ordered to assist in the building of a dam across the Red River, just above Alexandria, Louisiana. A military engineer from Wisconsin, Col. Joseph Bailey, had proposed, and the Union leaders agreed, to build a dam across the river which would cause the water level to rise, far upstream where the entire gunboat fleet of Admiral David Porter waited, stranded, above the upper falls, the water being too shallow for them to escape the oncoming Rebels to the safety of Alexandria and below. This event is rather famous in the history of both engineering and military operations.

Cpl. Theodore Wolbach describes the day:

The right arm of the 16th was detailed to assist on the dam. On the 30th of April they reported at Banks' headquarters, got their instructions, crossed the river and bivouaced near the rapids. Being the first troop on hand, there was a fair opportunity to forage in the immediate neighborhood. A supply of smoked meat was found packed in tubs and hid in a thicket. Some live stock was started up and chased through the woods. Arch Buckmaster brought one of them--a very fine beef--down by a marvellous off-hand shot at a hundred yards. Many books and other reading matter was found stowed away in unfrequented places. This furnished refreshing pastime for many during the hours of rest. ... While the right wing was at work on the dam the left wing was taking an active part in some lively work beyond our lines.

Wolbach's comments seem to imply the 16th Ohio was the first unit to be assigned the duty of building the famous dam.

A brief description of the plan of Col. Joseph Bailey to dam the Red River and save the Federal fleet:

The original plan by Col. Bailey was to build a main dam, just above the rapids, or lower falls, near Alexandria. The Federal fleet, however, was stranded above a second set of rapids known as the upper falls, several miles further upstream. These falls, or rapids, provided two, huge obstacles to the Federal fleet. Bailey believed that by damming the river above the lower falls, the water level would rise all the way up to the upper falls, allowing the gunboats to pass over the rapids through the deeper water. Once the eleven boats made it below the upper falls, they would congregate just above the dam. The dam would then be purposely breached at a precisely planned point and the boats would then pass through the deeper, rushing water, as it flowed over the lower falls, and reach the safety of the deeper water in front of Alexandria and beyond. Bailey's plan encountered some complications. Additional descriptions of the progress of the dams and the eventual outcome of events will be made in following Day-By-Day pages. See more detailed and complete descriptions of Bailey's Dam in the Red River Campaign section.

This period military map shows the approximate position of the 16th Ohio's left wing (very approximate), on picket duty guarding Alexandria, and the right wing on the opposite bank of the Red River helping to build Bailey's Dam, on April 30, 1864. The Federal gunboats, under Admiral David Porter, were trapped several miles upstream, above a set of rapids that were not navigable during low water.

This map shows the location of the dam, across the Red River just north of Alexandria, Louisiana, designed by Col. Joseph Bailey and built by troops investing the city and under Gen. Nathaniel Banks, including the 16th Ohio. The right wing of the 16th Ohio was probably the first unit assigned to begin building the dam, part of a desperate effort to raise the river level and allow the Federal gunboats, stranded above the upper rapids, to move down the river to safety. Many other soldiers would join them. The 16th Ohio began work on the east side of the river while other units worked from the west side.