Some of these are cultural, such as the U.S. use of the death penalty, some are international issues such as the Middle East peace process where the United States is often seen as pro-Israel and where Europe is often seen as pro-Arab (or at least neutral), and many others are trade related.
The current U.S. policies are often described as being unilateral in nature, whereas the European Union and Canada are often said to take a more multilateral approach, relying more on the United Nations and other international institutions to help solve issues.
Politically the United States tried to keep a distance from European affairs, and Canada was subordinate to British foreign policy.
During the First World War however both North American states found themselves fighting in Europe and engrossed in European politics.
The result was the North Atlantic Treaty Organization, which became the lynchpin of Transatlantic relations during the Cold War.