Which one is better, 1 or 2?

[NewHopeR]

1) The second half of the twentieth century witnessed a watershed of progress in the medical sciences.
2) The second half of the twentieth century was a watershed of progress in the medical sciences.

 

[charliedeut]

What's the context? Depending on it, both could be used.

 

[Rover_KE]

Please note that I have changed your thread title.

Extract from the Posting Guidelines:

'Thread titles should include all or part of the word/phrase being discussed.'