How do I handle a long gap on my résumé?

I took time out to care for a family member after working as a quality inspector. I am in Kansas City, in case local advice matters. I am not sure how much to explain. Did anyone get past it?

I listed the volunteering and course under the same dates and kept the explanation to a sentence in the cover letter.

I was hired after a 4-month gap. The manager said the skills test mattered more than the dates.