Herzl, however, succeeded in assembling several congresses at Basel (beginning in 1897), and at these congresses were enacted remarkable scenes of enthusiasm for the cause and devotion to its leader.
He represented New Jersey in the first and second Continental Congresses (1774,1775-1776), but left Philadelphia in June 1776, probably to avoid voting on the question of adopting the Declaration of Independence, which he regarded as inexpedient.
In 1774 and 1775 he was president of the first and second Provincial Congresses respectively, and he shared with Samuel Adams the leadership of the Massachusetts Whigs in all the irregular measures preceding the War of American Independence.
Towards 1847 he took part in the political agitation in Italy, and presided over scientific congresses, notably at Venice, where he declared himself in favour of the independence of Italy and the expulsion of the Austrians.
Kliiber, Acten des Wiener Congresses (9 vols.); Comte d'Angeberg, Le Congrbs de Vienne (4 vols.).