[The great expedition into Kentucky:--Early in January, Grant had been
directed to make a reconnoissance in favor of Brigadier-General Buell
who was confronting the Confederate General Buckner at Bowling Green.
One force under General Smith went up the west bank of the Tennessee
to threaten Forts Heiman and Henry. McClernand went into west
Kentucky, one column threatening Columbus, and another the Tennessee
River. Grant went with the latter. The object of the expedition was
attained; troops were not sent to reinforce Buckner. Grant was now
eager to move against the forts on the Tennessee. This is his errand
to St. Louis, to ask permission of General Halleck to move against
them. He had long been convinced that the true line of operations was
up the Tennessee and Cumberland Rivers. Once these rivers were held by
the Union troops, the Confederates would be forced to evacuate
Kentucky altogether. But General Halleck opposed the plan.