In 1860, the Philological Society launched its effort to create a dictionary more comprehensive than the world had ever seen; although the project would take more than 60 years to complete, the Oxford English Dictionary had been born.
1- would take more than 60 years to complete, the Oxford English Dictionary had been
2- took more than 60 years to complete, the Oxford English Dictionary was
3- would take more than 60 years to complete, the Oxford English Dictionary was being
4- would take more than 60 years to complete, the Oxford English Dictionary was
5- took more than 60 years to complete, the Oxford English Dictionary was about to be