An incident which probably occurred that winter illustrates the seriousness with which Lee viewed his family responsibilities. He and 8-year-old Custis had gone for a walk one snowy day, the boy following behind while his father broke the way. Preoccupied with ploughing through the deep snow, the father failed to look behind for some time, and when he did, saw that his little son was setting his feet carefully in the tracks his father had made, while imitating his every movement. “When I saw this,” Lee related afterwards, “I said to myself, ‘It behooves me to walk very straight, when the little fellow is already following in my tracks’.” LEE AT FORT HAMILTON, N. Y., 1841 TO 1846. Lee did not return to St. Louis until the summer of 1840, and then only to finish up his work and return home. There his fifth child, a girl, was born the following February. Soon after, Lee was sent to Fort Hamilton, N. Y., where he remained on duty until 1846. During these years it was customary for his family to be with him at New York during the summer and fall months and at Arlington the rest of the year, where Lee usually passed the winter. Two more children, a boy and a girl, were born in these years. Telling a friend about the arrival of the boy, Lee wrote: “About a month ago a young Robert E. Lee made his appearance at Arlington, much to the surprise and admiration of his brothers and sisters. He has a fine long nose like his father, but no whiskers.” WAR WITH MEXICO, 1846 TO 1848. Because war with Mexico seemed imminent when Lee went back to Fort Hamilton in the spring of 1846, Mrs. Lee and the children remained at Arlington. Hostilities began in May, and in August Lee was ordered to report for service in Mexico. Returning home, he spent a few days at Arlington arranging his affairs, then said goodbye to his family. Twenty-two months passed before he saw it again, months of anxiety for those waiting at home, relieved only by his long and frequent letters, such as the one he wrote to his two eldest sons the day before Christmas, 1846: “I hope good Santa Claus will fill my Rob’s stocking to-night: that Mildred’s, Agnes’s, and Anna’s may break down with good things. I do not know what he may have for you and Mary, but if he only leaves for you one half of what I wish, you will want for nothing!”