This organized service differed from that of Hale’s time in that it became a business with the men who conducted it, and enabled them usually to have some one who could get the information when they feared they were suspected or for any other reason they believed it too hazardous to undertake themselves. It is remarkable that although their lives were every moment in danger so carefully were their secrets guarded that not only to the end of the war but for a hundred and fifty years thereafter, in spite of frequent efforts to discover their identity the real men were never suspected. Primarily this was due to the caution of the men themselves, each declaring that if to any one other than those of their own selection they should learn that their names were known they would leave the service and never return; but it was also due to the care of General Washington in exacting from all who knew them the most solemn pledge that not to any one at any time or under any circumstances would they reveal their identity. It is interesting at this day to observe the fear they had that their handwriting might betray them, and to note that although they practiced several styles of writing with the intention of concealing their real hand nevertheless it was finally this that first enabled positive identification. It will also be discovered that although those in the Secret Service requested that the letters they were sending for General Washington should be destroyed the majority of them were preserved by him, and that on the contrary with one exception the letters from General Washington to the Culpers were promptly destroyed by them in order that they should not be betrayed thereby if searched. That the contents of so many of the letters to the members of the Secret Service from General Washington is known is due to his system of saving copies of them and these as a rule are in the handwriting of the General himself.