What did I buy?

We are grilling burgers tonight and I wanted oven fries, russet wedges and sweet potato wedges, with EVOO, rosemary, salt, pepper. I always buy some sort of sweet potato thing with dark pink skin, very orange flesh. Today they did not have any. But they had a regular sweet potato. I got home, peeled it, it is white inside, tough, and rather dry looking. What did I actually buy and is this thing going to cook like my russet?
I love sweet potato fries, because they caramelize and I especially love the combination of the two types.

White sweet potatoes are our favorites; particularly as candied at Thanksgiving. Have not tired to French Fry them. They are not as sweet as yams (the orange ones).

White sweet potatoes are our favorites; particularly as candied at Thanksgiving. Have not tired to French Fry them. They are not as sweet as yams (the orange ones).

Technically, they're both sweet potatoes (orange or white). You'd be hard-pressed to find yams in the U.S. (an African tuber that looks like a sweet potato, but is unrelated). To American slaves sweet potatoes looked similar to yams and were misnamed.

BTW, until about 1776 the word, "potato," meant "sweet potato." To end confusion, a dictionary at that time changed "potato" to mean the ordinary white spud.

Columbus discovered the sweet potato on his first trip and called them "portatoes"; white potatoes weren't discovered until about 90 years later in Peru. That's why there was so much confusion. When Shakespeare mentions a potato, he's really talking about a sweet potato.

Even today in the South, white potatoes are differentiated by the term, "Irish potatoes."