I would believe that steer that won the 1901 first international to be named advance not a 100% but pretty sure and yes he did have some white on his leg but there was a time you could show only angus steer with white on places other than behind the navel. If that steer was advance the americas oldest purebred angus herd raised him the Pierces also known as Woodlawn Farms Il and here is a section about the angus history that will solve my shorthorn friends myth
Shorthorn Breed Threatens the Aberdeen-Angus. In 1810, the Colling brothers of England sold the famous Shorthorn bull Comet at $5,000. The publicity resulting from this sale naturally spread throughout Scotland, and many breeders looked with favor upon the use of Shorthorn blood in improving the native cattle. Subsequently good herds of Shorthorn cattle were established in Scotland, and the cattle were used in the improvement of native stock. The use of the Shorthorn cattle on the black native cows was a very common practice of the period for the raising of commercial stock. This practice of crossbreeding threatened the Aberdeen-Angus breed with extinction.
It is often suggested that some Shorthorn blood found its way into the Aberdeen-Angus breed prior to the time the Herd Book was closed. Alexander Keith, secretary of the Aberdeen-Angus Cattle Society from 1944 to 1955, takes exception to this opinion by writing:
The statement has been frequently made that shorthorn blood was introduced into the Aberdeen-Angus breed at an early stage of its existence. There is no foundation whatever for such a statement. The tribes from which the Aberdeen-Angus breed were drawn were supplying England with beef cattle for generations before what became the beef Shorthorn was taken across the Border into Scotland and improved into what is known as the Scotch Shorthorn. Of the Aberdeen-Angus pioneers, Hugh Watson had a certain number of Shorthorn cattle, but it is quite evident from his won remarks and his insistence upon the blackness of his Aberdeen-Angus cattle that he would never have permitted mixing them. And McCombie: when one or two farmers introduced the Teeswater or Shorthorn breed into his neighborhood he drove them out by completely dominating the local shows with his Aberdeen-Angus black polls. The feeling of the early improvers of Aberdeen-Angus cattle may be gathered from the fact that my own grandfather, who was one of McCombie’s friends and associates, would not allow anything but a black beast on his farm and in his old age when I was a young boy he would insist that if I ever became a farmer and wished to be a successful feeder of cattle I must stick rigidly to the Blacks.
Reference:
Briggs, H.M. & D.M. Briggs. Modern Breeds of Livestock. Fourth Edition. Macmillan Publishing Co. 1980 (reprinted with permission from Dr. Briggs).