Sentence Correction (SC) | Re: In 1860, the Philological Society launched its effort to create a dict

I agree with the post above. Without background knowledge on dates, what stops me from thinking that 1. they launched the project 2. the project took 60 years to complete 3. completion resulted in the Oxford Dictionary.

Following that logic/timeline, is it still incorrect the use of simple past for the (2.) part or my mistake on this question was solely based on not getting the timeline right?

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