Impediments and enablers: The rivers that hindered and aided Sherman’s March

The March to the Sea has long been a favorite topic of mine.  Having driven, walked, bicycled, and boated the route, along with hosting the occasional tour, the topic emerges as an old friend with whom I have many stories to share.  As I’ve written for each installment thus far, the challenge is to put together the story without wandering into some lengthy post.  Such leads into two-a-day postings!

As with much of my approach to studying the Civil War, my appreciation is firmly attached to the ground itself.  Or, perhaps for this post the rivers.  Earlier today I mentioned the Ocmulgee River as the first major river barrier to Sherman’s march.  Running generally north to south, the river and its tributaries lay directly across the line of march on November 17-19, 1864.  And the Ocmulgee was not the only such barrier.  Consider the “big” map of Georgia again, this time with the major rivers highlighted in blue:


A little larger scale than I like, and you may want to click on the picture and open in Flickr’s full screen mode.

For orientation, Atlanta is in the upper left.  We have the Chattahoochee River flowing from just north of that city, then down the state’s western border.  The Flint River flows from south of Atlanta down to join the Chattahoochee.  Working to the right, we see the Ocmulgee and Oconee, which join to form the Altamaha River flowing down past Darien.  Two small coastal rivers south of there are the Satilla and St. Mary’s, which we’ve discussed in relation to coastal raids.  North of the Altamaha is the Ogeechee River system that includes the Cannoochee.  Finally on the state’s eastern border is the Savannah River, with tributaries that include Briar Creek, and the smaller Ebenezer Creek.

In general, we see in Georgia the rivers of the Piedmont flow south.  But once onto the coastal plain those rivers reach the coastal plain, the flow turns southwest. Draw a line from Atlanta to Savannah.  You’ll see the Ocmulgee and Oconee intersect that line, though not quite a right angles.  But the Ogeechee intersects at a slight angle.

Now let me overlay on the map of rivers a set of lines showing the general line of march for the two wings of Sherman’s force (generally… roughly… in light green):


A few observations here.  First, if we follow convention a military commander should select a route of march that reduces the number of river crossings.  Without putting a single red line (Confederate) on the map, a route that required practically no major river crossings would pass just west of Macon, south around the Ocmulgee, then to the sea on the south side of the Altamaha.  Such a line of march ends at Brunswick, a port city that was for all practical purposes abandoned by the Confederates (and frequently visited by the Federal Navy).  Of course, that route avoids the “prize” of Savannah.  Marching north from Brunswick would have similar barriers encountered by the force outside Charleston – narrow lines of approach bounded by marsh and swamp.

Furthermore, such a march played directly into the Confederate strength.  Macon and Columbus were garrisoned and fortified.  Any close passage would require the Federals to reduce if not neutralize those forces. And this was exactly what the Confederates expected.

However, flip that around on the map-board.  Once the Federals crossed the Ocmulgee, in order to pursue with the forces out of Macon the Confederates would have to make river crossings of their own.  Maybe the Ocmulgee somewhat a Rubicon for the campaign.  Once across, Sherman could not return to Atlanta without difficulty.  He was, at that point, completely detached from any support.  However it was also a barrier in his rear that blocked pursuit.  The Oconee provided a second such barrier – both a Rubicon and shield at the same time.  And once past those Rubicons, the Altamaha to the south and Briar Creek to the north offered flank protection.

Into the drainage basin for the Ogeechee River, the line of march goes with the “grain” of the watershed.  That river formed a divide between the two wings.  Such made mutual support difficult.  Tributaries offered several points at which the Confederates could stall the march with only a small, well placed force. Again, not a “textbook” route selection.

But, the river’s split also worked in the favor of the Federals.  At no point could the Confederates form a favorable line, using those tributaries, where both wings could be stalled.  Every one of those potential points of resistance could be flanked from the other side of the Ogeechee.

Most important for the line of march, the route placed the two wings of the army at a convergence on dry ground west of Savannah.  While the marshes and coastal waterways still forced the large force onto some narrow lines of approach, those were much better than from the south or east.  The only difficulty would be establishing some connection to the sea, to facilitate resupply and coordination with other forces.

At any rate, you can see the rivers were an important factor in the march to the sea.  I think so, at least.  If nothing else, those gave me ample excuse over the years to combine fishing trips with Civil War field research!