On March 1, a large group of Mormons began leaving the camp. Brigham Young, president of the Quorum of the Twelve Apostles, which lead the Church after Joseph Smith's death, had hoped that he could get a group of Mormon Pioneers all the way to the Salt Lake Valley that year, but travel across Iowa was slow. There were heavy rains, and the ground thawed, causing it to be muddy and hard to drive through with oxen and heavy wagons. Because traveling was taking so long, food supplies began to run low, and because of the weather, many were sick. The living conditions caused many problems.