Owing to reasons that cannot be stated here, the peace of 1814-15 led up to no effective union: it even perpetuated the old dualism of interests.

But once more the hostility of France under a Napoleon strengthened the impulse to German consolidation, and on this occasion there was at hand a man who had carefully prepared the way for an abiding form of political union; his diplomatic campaign of the last seven years had secured Russia's friendship and consequently Austria's reluctant neutrality; as for the dislike of the Southern States to unite with the North, that feeling waned for a few weeks amidst the enthusiasm caused by the German triumphs.

The opportunity was unexampled: it had not occurred even in 1814; it might never occur again; and it was certain to pass away when the war fever passed by.

How wise, then, to strike while the iron was hot! The smaller details of the welding process were infinitely less important than the welding itself.
One last consideration remains.

If the opportunity was unexampled, so also were the statesmanlike qualities of the man who seized it.