Continental drift is a hypothesis put forward in the early 20th century by German polymath Alfred Wegener. Based on the observed close fit between the coasts of eastern South America and western Africa, Wegener proposed the idea that the continents shifted position over time. The concept was largely rejected due to a lack of proposed mechanism until the 1960s, when seafloor spreading was discovered at midoceanic trenches; from then on, continental drift was incorporated into the theory of plate tectonics, where internal currents in the Earth's mantle led to gradual shifting of large sections of the crust.
Acceptance of continental drift was delayed due to a number of factors, not the least of which was Wegener's insistence on an impossible mechanism (continents "plowing" through the ocean floor). Also a factor was geologists' avoidance of the evidence that Wegener did have, something now considered to have been a mistake. 
Continental drift has since been observed using sophisticated positioning equipment placed along major fault lines, as well as satellite observations. As you might have guessed, the continents are not moving very fast, about the same rate as your finger nails grow.
 See also
- ↑ However, overall, the delay in success of the continental drift theory can be considered an object lesson in what happens when a scientist who happens to be right is a jerk about it.