Here is one obituary. Tilly was a historical sociologist but he had an influence on economic history as well, including the New Institutional Economics:
Dr. Tilly mined immense piles of original documents for raw data and
contemporary accounts – including municipal archives, unpublished
letters and diaries – that he used to develop theories applicable to
many contexts. A particular interest was the development of the nation
state in Europe, which he suggested was partly a military innovation.
In his 1990 book “Coercion, Capital, and European States, AD 990-1990”
(Blackwell), he argued that the increasingly large costs of gunpowder
and large armies required big, powerful nation states with the power to
In 1985, he gave early indications of his argument that war
made states in an article that said nation states, with their
monopolies on violence, function like gangsters’ protection rackets. He
said that governments emphasize, create and stimulate external threats,
then ask their citizens to pay for defense.
I think of his mid-career work as being most important, such as his The Formation of National States in Western Europe. In any case America has lost one of its leading social scientists. Wikipedia offers good links. Here is Tilly on how to do social science work, recommended.