My City - Mill District

The foundation of Minnesota's economy was beaver fur used to make top hats when it was all the rage in Europe.
Next step was for the railroad to be built by James J. Hill, connecting the Midwest with the rest of the continent. Once established, the rail road was used to transport grain from all over the region to the flour mills of Minneapolis, which made a significant contribution to the growth of the local economy, and it's still an important piece.

What you see is the first lock and dam, built by the Army Corps of Engineers. Hydro power powered the mills via a very complicated gear train from turbine to the drive axles of the mill stones.