at first
Initially, at the start, as in At first the berries were green, but when they ripened they turned bright red. [Second half of 1500s]
Related Words for at first basically, formerly, primitively, first, primarily, incipiently, initially, originally Examples from the Web for at first Historical Examples of at first
Even Mr. Seward, cautious and conservative diplomat as he was, at-first “opposed any concession or surrender of the prisoners.”
The Every-day Life of Abraham Lincoln
Francis Fisher Browne