When Bragg's position became known to Rosecrans, great was his haste to effect the concentration of his army. Couriers dashed toward Alpine with orders for McCook to join Thomas with the utmost celerity. The former started at once, shortly after midnight on the 13th, in response to Thomas's urgent call. It was a real race of life and death, attended by the greatest hardships. Ignorant of the roads, McCook submitted his troops to a most exhausting march, twice up and down the mountain, fifty-seven miles of the most arduous toil, often dragging artillery up by hand and letting it down steep declines by means of ropes. But he closed up with Thomas on the 17th, and the Army of the Cumberland was saved from its desperate peril. Crittenden's corps now took position at Lee and Gordon's Mills on the left bank of Chickamauga Creek, and the Federal troops were all within supporting distance. In the Indian tongue Chickamauga means "The River of Death," a name strangely prophetic of that gigantic conflict soon to be waged by these hostile forces throughout this beautiful and heretofore peaceful valley. The Confederate army, its corps under Generals Polk, D. H. Hill, and Buckner, was stationed on the east side of the stream, its right wing below Lee and Gordon's Mills, and the left extending up the creek toward Lafayette. On the Federal side Thomas was moved to the left, with Crittenden in the center and McCook on the right. Their strength has been estimated at fifty-five to sixty-nine thousand men. On the 18th, Longstreet's troops were arriving from Virginia, and by the morning of the 19th the greater part of the Confederate army had crossed the Chickamauga. The two mighty armies were now face to face, and none could doubt that the impending struggle would be attended by frightful loss to both sides. It was Bragg's intention to send Polk, commanding the right wing, in a flanking movement against the Federal left under Thomas, and thus intervene between it and Chattanooga. The first encounter, at 10 o'clock in the morning of the 19th, resulted in a Confederate repulse, but fresh divisions were constantly pushed forward under the deadly fire of the Federal artillery. The Federals were gradually forced back by the incessant charge of the Confederates; but assailed and assailant fought with such great courage and determination that any decided advantage was withheld from either. Meanwhile, the Federal right was hard pressed by Hood, commanding Longstreet's corps, and a desperate battle ensued along the entire line. It seemed, however, more like a struggle between separate divisions than the clash of two great armies. When night descended the Federals had been forced back from the creek, but the result had been indecisive.