Did it exist in older cultures? Ancient ones? How was it done?
I can only speak to references I have come across in my studies, whic were some time ago. I do recall that Juvenal, a Roman poet of the 1st & 2nd centuries AD, mentions abortion in [Satire VI] (http://www.poetryintranslation.com/PITBR/Latin/JuvenalSatires6.htm#anchor_Toc282858852). This satire is intensely misogynistic, and quite offensive in that respect.
The poem has two mentions; to abortion as acheived through abortificants, which means a substance consumed to induce a miscarraige. The other is to 'the abortionist', who would have known which substances would have this required effect. There is little other information in the poem, and Juvela does not specify what substances, the exact role of the abortionist, or how one would be procured.