's command was, at this time, sent out as far as the Big Black river
, to obstruct the approaches to Vicksburg
from the east, and to destroy all the railroad bridges and forage that could be reached.
‘All trains and cattle should be brought in, and every thing done to prevent an army supplying itself coming this way. Wherever there is a bridge or trestle-work, as far east as you send troops, have them destroyed.’
On the 26th, Grant
also sent a force of twelve thousand men, under Blair
, to drive off a body of the enemy supposed to be collecting between the Big Black river
and the Yazoo
This command was not expected to fight Johnston
, but simply to act as a corps of observation, and to destroy all stock, forage, roads, and bridges as it returned.
moved along the Yazoo
about forty-five miles, and effectually accomplished the purpose of his expedition, preventing Johnston
from moving upon Vicksburg
in that direction, and also from drawing supplies in the fertile region between the two rivers.
He was absent nearly a week, and reconnoitred the whole region thoroughly.
On the 31st, Grant
wrote: ‘It is now certain that Johnston
has already collected a force from twenty thousand to twenty-five thousand strong, at Jackson
and is using every effort to increase it to forty thousand.
With this he will undoubtedly attack Haine
's bluff, and compel me to abandon the investment of the city, if not reenforced before he can get here.’
was accordingly requested to direct a brigade of amphibious and useful troops at his disposal, known as the Marine
brigade, to debark at Haine
's bluff and hold the place until relieved