The difference between Come about and Come to pass

When used as verbs, come about means to come to pass, whereas come to pass means to happen.

check bellow for the other definitions of Come about and Come to pass

Come about as a verb (intransitive):

To come to pass; to develop; to occur; to take place; to happen.

Examples:

"We have to ask, how did this come about?"
Come about as a verb (intransitive, nautical):

To tack; to change tack; to maneuver the bow of a sailing vessel across the wind so that the wind changes from one side of the vessel to the other; to position a boat with respect to the wind after tacking. See also .
Come about as a verb (intransitive):

To change; to come round.