We took a family vacation to Chicago, IL to visit museums. We stayed 3 nights in a hotel. Then, we headed over to Michigan Adventures theme park & water park near Muskegon, MI. I've traveled with infants and toddlers before, but I have to say that this stage (crawling) was the toughest stage for traveling. I'll share my insights...
If you have an infant (non-crawling), then much of the trip happens with baby in the stroller, or in a sling. If your baby sits independently, then sometimes the baby can sit on a blanket on the ground, as you hand her toys for playing with. I managed the Michigan homeschool conference for 2 days like this (she was just starting to creep forward a little).
If you have a walking toddler, then they are probably also eating food and drinking from a sippy cup. Most of the trip will be spent chasing a walking toddler, and dishing out drinks and a constant supply of snacks. It's not easy per say (you're constantly on the move!), but it's definitely do-able.
If you have a crawling baby, it becomes more of a challenge. My baby, in particular, thinks that sippy cups and snacks are for amusement purposes only (drink & spit it out, chew & spit it out - and then whine about it, and refuse any more). The baby will not be contained in a stroller (too much to do!) The baby is on hands and knees, where all the foot traffic and garbage go. There really isn't a whole lot to do with baby in this stage.
I found that the Chicago Museums (Adler Planetarium, Field Museum, & Science/Industry) had a special area reserved for younger children. These were exploration rooms for babies, toddlers, and young children. This was a perfect hangout for my crawling baby. Daddy & the kids explored the museums while I hung out in the young children's rooms. I'd catch up with the family during baby's naptimes, and catch a glimpse of this or that.
MI Adventures Theme Park was HORR-I-BLE with a capital H for crawling babies. The kiddy pool areas were meant for walkers (the ground was too scratchy for the baby, and she kept crawling into the deeper end). I put long pants over her swim diaper, and tried to keep her head above water. The rides were worse: the only thing a non-walker can go on is: carousel (seats only, not animals), train, and ferris wheel. This was less exciting to the crawling baby than a car ride (and she really doesn't like car rides, either). The ground is all cement and covered by gooey foods, foot traffic, wrappers, and the possibility that someone vomitted there after a ride. I tried to find wooden platforms and bridges for her to crawl on. There really is no place for a crawling, non walking, non-stroller riding baby. If you have a crawling baby, I suggest waiting until that baby is walking before making the trip to an amusement park.