Petersburg as State Capital?
In a word, no.
The Woodford County town was laid out by General Charles Scott(Wikipedia), with anticipation of it becoming the capital.
The legislature at the time opted to make the capital whichever town anted-up the most, and Frankfort, under the leadership of the infamous General James Wilkinson (Wikipedia), came up with land, rent from a tobacco warehouse for 7 years, building supplies, and $3,000 in gold. No place else was even close.
General Scott went back to fighting Indians, and today, you'll look hard to find Petersburg on a Woodford County map.
The Petersburg in Boone County was never a candidate. Sorry.