In one aspect, then, the Union was the only feasible way of carrying out the principle which underlay the successful establishment of Colonial self-government.  In another aspect it was the last step of a natural and, indeed, inevitable process for which the history of the British Colonies since the grant of self-government has furnished analogies in abundance.  It has furnished none for the reversal of that process.  It is only necessary to consider the reasons which, in various degrees, influenced the several groups of independent Colonies in North America, Australia, and South Africa to unite under a single government, whether federal or unitary, thus wholly or partially surrendering the “Home Rule” previously enjoyed by them, in order to see how close is the parallel.  The weak and scattered North American Colonies were at a serious disadvantage in all political and commercial negotiations with their powerful neighbour, the United States, a fact very clearly emphasised by the termination of Lord Elgin’s reciprocity treaty in 1864.  None of them was in a position to deal with the vast territories of the North-West, undeveloped by the Hudson’s Bay Company, and in imminent danger of American occupation.  A common trade policy, a common railway policy, and a common banking system were essential to a rapid development of their great resources, and only a common government could provide them.  In Australia the chief factor in bringing about federation was the weakness and want of influence of the separate Colonies in dealing with problems of defence and external policy, impressed upon them by German and French colonial expansion in the Pacific, and by the growth of Japan.  In South Africa, on the other hand, the factors were mainly internal.  The constant friction over railway and customs agreements, continually on the verge of breaking down, embittered the relations of the different Colonies and maintained an atmosphere of uncertainty discouraging to commercial enterprise.  Four different governments dealt with a labour supply mainly required in one colony.  Four agricultural departments dealt with locusts and cattle plagues, which knew no political boundaries, and which could only be stamped out by the most prompt and determined action.  Four systems of law and four organisations for defence secured, as Lord Selborne pointed out in a striking Memorandum (Blue Book Cd. 3564) a minimum of return for a maximum of expense.  A native rising in Natal warned South Africans that the mistake of a single Colony might at any moment set the whole of South Africa ablaze with rebellion.  In the absence of larger issues local politics in each Colony turned almost exclusively on the racial feud.  A comprehensive union alone could bring commercial stability and progressive development, mitigate race hatred, and pave the way to a true South African nationality.