It is not surprising, in view of the unlawful nature of Underground Railroad service, that extremely little in the way of contemporaneous documents has descended to us even across the short span of a generation or two, and that there are few written data for the history of a movement that gave liberty to thousands of slaves. The legal restraints upon the rendering of aid to slaves bent on flight to Canada were, of course, ever present in the minds of those that pitied the bondman, whether a well-informed lawyer, like Joshua R. Giddings, or an illiterate negro, who, notwithstanding his fellow-feeling, was yet sufficiently sagacious to avoid the open violation of what others might call the law of the land. Therefore, written evidence of complicity was for the most part carefully avoided; and little information concerning any part of the work of the Underground Road was allowed to get into print. It is known that records and diaries were kept by certain helpers; and a few of the letters and messages that passed between station-keepers have been preserved. These sources of information are as valuable as they are rare: they would doubtless be more plentiful if the Fugitive Slave Law of 1850 had not created such consternation as to lead to the destruction of most of the telltale documents. The great collection of contemporaneous material is that of William Still, relating mainly to the work of the Vigilance Committee of Philadelphia. The motives and the methods of Mr. Still in keeping his register are given in the following words: "Thousands of escapes, harrowing separations, dreadful longings, dark gropings after lost parents, brothers, sisters, and identities, seemed ever to be pressing on my mind. While I knew the danger of keeping strict records, and while I did not then dream that in my day slavery would be blotted out, or that the time would come when I could publish these records, it used to afford me great satisfaction to take them down fresh from the lips of fugitives on the way to freedom, and to preserve them as they had given them...."[14] When in 1852 Mr. Still became the chairman of the Acting Committee of Vigilance his opportunities were doubtless increased for obtaining histories of cases; and he was then directed as head of the committee "to keep a record of all their doings, ... especially of the money received and expended on behalf of every case claiming their interposition."[15] During the period of the War, Chairman Still concealed the records and documents he had collected in the loft of Lebanon Cemetery building, and although their publication became practicable when the Proclamation of Emancipation was issued, the _Underground Railroad Records_ did not appear until 1872.[16] [14] _Underground Railroad Records_, pp. xxxiii, xxxiv. [15] _Ibid._, p. 611, where is printed an article from the _Pennsylvania Freeman_, December 9, 1852, giving an account of the formation of the Committee.