In accordance with this rule, it may safely be assumed that the forefathers of Boston had built the first prison-house, somewhere in the vicinity of Cornhill, almost as seasonably as they marked out the first burial-ground, on Isaac Johnson's lot, and round about his grave, which subsequently became the nucleus of all the congregated sepulchres in the old church-yard of King's Chapel. What is the meaning of this excerpt

The meaning of this passage is to show how the cemetery has increased in size over time.

Explanation:

The text shows that a prison and cemetery were built a long time ago at Cornhill. This cemetery, in fact, had only one grave, which was where the tomb of Isaac Johnson, the owner of the land, would be. However, as time passed, this cemetery grew intensely, because around the tomb of Isaac Johnson, more tombs were placed, forming a large area of assembled graves.

A on EDGE 2021

Explanation:

The prison and cemetery were built early, with the cemetery expanding in size from its original plot.

greet them:

buenas noches.

that is considered night time which is when "good night" is used.