What geographic feature did the British
encounter on their
advance route but not
on their retreat?

The main geographic feature that formed the boundary of the thirteen British colonies in North America was the Appalachian Mountains.

Explanation:

Britain’s long coastlines, its many natural harbors (including the deepest natural harbor in Europe) and inlets and its navigable rivers hugely impacted its development as a nation. For example, Britain’s natural resources perfectly situated it to become a naval power. And its geographical vulnerability forced it to become one.

The topography of Great Britain consists mainly of low, gently rolling hills in the eastern and southern portions of the island and hills and low mountains in the western and northern regions. The climate of Great Britain is temperate and it is moderated by the Gulf Stream.

After the British arrived in Boston, they set out on a course toward Concord, Massachusetts, to capture rebel leaders Samuel Adams and John Hancock and destroy the colonists' supply of weapons and ammunition. Their first stop was in Lexington, where the battle on April 19, 1775

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