Tomb Sweeping Day

Tomb Sweeping Day is one of the most significant folk customs in China, and has a long history. People of Han and most of the minority groups will visit their ancestral graves mourning the deceased, which is also a way of showing their respect for their family and extending their gratitude to their ancestors.....

Or, simplified:

Tomb Sweeping Day has a long history and is one of the most significant folk customs of China. People of Han and most minority groups visit their ancestral graves mourning the deceased. It is a way of showing respect for their family and extending gratitude to their ancestors.....

They are both correct. I’ve just tried to keep your wording in the first example and written it with my brain in the second. I hope I haven’t lost any of your meaning.