Usually this happens if your kitchen is on the cooler side. If it is, I recommend boiling some water and pouring it into 2 mugs. With the oven *OFF* place your dough inside with the 2 mugs of boiling water on each side. This will create a faux humidity and will activate the yeast faster. Sometimes, you do have slow acting yeast. Wait another hour to see if it will rise. If it still has a minimal rise the last resort is to still leave it overnight. After leaving it overnight and it still does not rise, I'm afraid you have dead yeast. That is extreamly rare. If that does happen I would start again.