Also depends on what you mean by leaving the ends of the sleepers exposed: fully exposed, or partially, and on era, company, location.
North American practice stems from laying track quickly across vast distances, where ties were spaced by the length of a workman’s boot between them. With such an approach, staggered railjoints - occuring just where they fall - make sense. As for ballast, there often wasn’t any.
From this evolves a different approach to suspension: the classic American 4-4-0* is compensated with the front truck (bogie) as one of three points, the other two being either side of the firebox. Rolling stock has trucks, etc, as the permanent way is often hard riding and uneven.
In the U.K., the track was part of the “total suspension system”, with deep ballast and the wooden keys to the bullhead rail providing dampening, accommodating a more rigid design of locomotive frame.
All “Americans” are 4-4-0s, but not all 4-4-0s are American.