By the 30th it became obvious to both sides that the Confederate right at Five Forks was in jeopardy. Grant discusses this in his memoirs:
The next day, March 30th, we had made sufficient progress to the south-west to warrant me in starting Sheridan with his cavalry over by Dinwiddie with instructions to then come up by the road leading north-west to Five Forks, thus menacing the right of Lee’s line.
This movement was made for the purpose of extending our lines to the west as far as practicable towards the enemy’s extreme right, or Five Forks. The column moving detached from the army still in the trenches was, excluding the cavalry, very small. The forces in the trenches were themselves extending to the left flank. Warren was on the extreme left when the extension began, but Humphreys was marched around later and thrown into line between him and Five Forks.
My hope was that Sheridan would be able to carry Five Forks, get on the enemy’s right flank and rear, and force them to weaken their centre to protect their right so that an assault in the centre might be successfully made. General Wright’s corps had been designated to make this assault, which I intended to order as soon as information reached me of Sheridan’s success. He was to move under cover as close to the enemy as he could get.
It is natural to suppose that Lee would understand my design to be to get up to the South Side and ultimately to the Danville Railroad, as soon as he had heard of the movement commenced on the 29th. These roads were so important to his very existence while he remained in Richmond and Petersburg, and of such vital importance to him even in case of retreat, that naturally he would make most strenuous efforts to defend them. He did on the 30th send Pickett with five brigades to reinforce Five Forks. He also sent around to the right of his army some two or three other divisions, besides directing that other troops be held in readiness on the north side of the James River to come over on call. He came over himself to superintend in person the defence of his right flank.
For nine months Grant had been gradually extending his lines to the west, with Lee forced to follow suit. Lee knew that with his smaller army there would come a day when his forces would be stretched too thin and that Grant would be able to break his lines. On March 30, 1865, both Lee and Grant could see that this day was at hand.