Serious Eats - seriouseats.com

your yeast may have been old or dead. proof some in some warm (not hot) water to see if it "blooms."

I doubt it was the yeast being completely dead -- if it was, it wouldn't have risen at all.

It might have been that you didn't knead it enough. Kneading activates the gluten, which is what makes the dough stretchy and able to hold all the gas bubbles that the yeast creates. If the gluten is too weak, the bubbles pop and you've got a dense bread. When the dough is kneaded properly, it will be smooth and shiny and very elastic. You should be able to take a small piece of dough and stretch it so thin that you can see through it. This is called the windowpane test. If you look it up online, you might find photos.

It also may be that you didn't let it rise enough before it went into the oven. And/or you didn't let it rise enough the first time. If you're going by the clock when following directions, the results aren't going to be as good as if you go by the results. Let the dough have enough time to rise properly, even if the recipe says it should be done in less time.

Make sure you're not adding garlic salt and onion salt instead of the powders. You need a little salt in the bread since it regulates the yeast, but too much salt can slow it down more than you want. Different herbs and spices can affect the way the dough behaves, but if you're just adding a little bit, it shouldn't make a huge difference in the final product.

Your dough may not have been wet enough. The problem usually is the way people measure flour. If you can find recipes that use weight in addition to cup measurements, you'll get a better idea of how much flour you really need. Also, you might be adding too much extra flour as you knead, if you're doing it by hand. I use about 2 1/2 cups of flour per cup of water when I make bread, but it can be as little as 2 cups, depending on what kind of flour it is and what kind of bread I'm making. I might go as high as 3 cups of flour, but that's pretty unusual.

The drier the dough is, the longer it takes to rise, too.

Last, if you're looking for a soft, fluffy, pillowy texture, add some mashed potato or some instant potato flakes to the dough. Not a lot. I usually use the potato flakes because they're handy, and I add maybe a quarter cup to a loaf of bread (I make one loaf at a time, where most recipes are for 2 loaves).