In this article on Yaa Gyasi in SF Gate by Eli Wolfe, Wolfe describes Gyasi’s writing process while she was a student at the University of Iowa:
She was relieved when she was accepted to the Iowa Writers’ Workshop in 2012. In Iowa, Gyasi was finally able to unpack the novel she had been carrying around for three years. Gyasi worked slowly and methodically, sometimes advancing only 200 words a day. But when she completed the novel in 2015 and her agent sent it to publishers, the offers flooded in immediately, culminating in a seven-figure advance that she received from Knopf.
Wolfe, Eli. “How Yaa Gyasi Found Her Story in Slavers’ Outpost.” SFGate, San Francisco Chronicle, 28 June 2016.