This task is about reading the given passage and construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) its answer is a continuous text span from the paragraph. Avoid creating questions that (i) can be answered correctly without actually understanding the paragraph and (ii) uses same words or phrases given in the passage.

Natives of North America began practicing farming approximately 4,000 years ago, late in the Archaic period of North American cultures. Technology had advanced to the point that pottery was becoming common and the small-scale felling of trees had become feasible. Concurrently, the Archaic Indians began using fire in a controlled manner. Intentional burning of vegetation was used to mimic the effects of natural fires that tended to clear forest understories. It made travel easier and facilitated the growth of herbs and berry-producing plants, which were important for both food and medicines.
When did the North American natives begin farming?