In the 1850's and 60's, Chicago was raised by more than 6 feet to improve drainage. They used the same process now as then to do it. Then as we all know, it all burned down anyway within 15 years.
Galveston was raised after the hurricane at the turn of the last century. 17 feet to be exact.
Also on the topic of local feats of engineering, maybe you know that a canal was dug and the flow of the Chicago River was reversed to empty to the Mississippi instead of the lake for sanitary reasons.
I didn't know that the south fork of the south branch of the river, known as Bubbly Creek, is where the meat packing factories of The Jungle were. Turns out all the animal waste dumped screwed up the ecology of the river and left a 2m thick layer of decomposing blood at the bottom.