What does the underlined WHICH stand for?

The passage below comes from Don't Know Much About History by Kenneth C. Davis.

New Amsterdam developed far differently from the English colonies, which held out the promise of land ownership for at least some of its settlers. Promising to bring over fifty settlers to work the land, a few wealthy Dutch landholders, or patroons, were able to secure huge tracts along the Hudson in a system that more closely resembled medieval European feudalism than anything else, a system that continued well after the Revolution and that contributed to New York’s reputation as an aristocratic (and, during the Revolution, loyalist) stronghold.

I have one major question and a minor one for this paragraph.

First, for a major, what does the underlined WHICH stand for? It seems to me that ‘English colonies’ be the one. Am I right?

https://www.thefreedictionary.com/hold+out

Last, for a minor, I think the meaning of the underlined ‘held out’ is #1 meaning of the above website, that is ‘To present or offer’. Am I right?

Thanks.