- The 19th century was marked by the abolition of slavery.
- The 19th century marked the abolition of slavery.
Which is correct?
The meaning is that the abolition of slavery was an important event in the 19th century.
Which is correct?
The meaning is that the abolition of slavery was an important event in the 19th century.
Taking up the point raised in comments by StuartF, a stretch of time is marked by (i.e. characterized by) certain features and a particular point in time (such as a particular year in a century or a day on the calendar) marks (i.e. stands as the end or beginning) of something.
A stretch of time can be marked by ongoing trends or conflicts, say, and a point in time can mark the occasion when something takes place.
14th century England was marked by the plague.
Labor Day marks the end of the summer in the US.
I think that, while both may work, I would use the second option here. "Was marked by" has, to me, negative connotations - as if the abolition of slavery was some sort of a stain, a big negative thing that defined the century (a mark), which I, and most people (I hope) very much disagree with. The second option also seems more natural to me. If you wanted to talk about something negative you may choose to use the first option, but to me it really does just imply a large negative defining event. Perhaps that's just me though. Since both are grammatically correct it's ultimately up to you which you choose, I just thought I'd offer up my opinion. In a more academic context you might want to use option 1 purely because it is "more" correct - see j D3V's answer. But in general use both work.
If you want to say that “the abolition of slavery was an important event in the 19th century,” why not just say it?
Your two formulations are more subject than this straight-forward statement to interpretations that you apparently don’t want, and therefore create puzzlement rather than clarity for the reader.
#1 is the correct sentence because, the 19th century was most certainly marked by the abolition of slavery, however; the abolition of slavery was not marked by the 19th century (that might sound redundant, if it does, think about it).
I would also argue that the abolition of slavery was not significant because it happened in the 19th century, but rather, the 19th century was significant, because the abolition of slavery took place with-in the 19th century