The Truman Library is great. I don't have much other suggestions - seems like it's a long time you're spending in Kansas City...

I visited KC last year on a day trip from Dallas. Went to the Art museum and Contemporary art museum. Here's my short trip report if you're interested:
http://www.fodors.com/forums/threadselect.jsp?fid=1&tid=34808796

There is a WWI Memorial/Museum across from Union Station and Crown Center. It is brand new, and receiving rave reviews.

At City Market, on the river, there is the Steamboat Arabia Museum.

West of KCK, is a NASCAR track and a huge sporting goods store: Cabelas.

Presuming you're staying on the Plaza...

Nelson-Atkins Museum of Art- A lovely gallery. The new wing will be open by then.

Restaurants on/near the Plaza- Aixois (French), Andre's (Swiss), Cafe Sebastienne (in Kemper Museum of Contemporary Art). If you don't mind chains, then Capitol Grille, McCormick & Schmick's, and Ruth Chris. For BBQ, Jack Stack about 5 miles away downtown.

If not staying on the Plaza, then let us know where. Enjoy, and expect a quite nice but humid visit. annieladd

You already have plenty of good advice on attractions, so I will just tackle the restaurants.

BBQ: There are a great many good options, but Arthur Bryants is the quintessential KC BBQ. It is just a few blocks from the Negro League Museum and KC Jazz Museum.

Steak: Also a lot of good options here. My favorite place is out south: CC's City Broiler in Overland Park. Best steak in KC and reasonable. But that is too far to go just for that. You might combine it with a visit to the Overland Park Arboretum. Closer in places include the Majestic and Golden Ox.

Italian: Lydia's is in a restored freight house near Union Station (same building as Jack Stack BBQ). My favorite is Garozzo's Ristorante. Go to the original location east of the City Market.

Chinese: Bo Ling's for Dim Sum on the weekend. Genghis Khan for great Mongolian BBQ on Bell Street near KU Medical Center.

Korean: Chung's Rainbow Restaurant in Overland Park, just a tiny storefront with a few tables, but great food.

Indian: There are many good options, but Ruchi Indian Restaurant in Overland Park, and
Swagat Authentic Indian Cuisine up near the airport are as good as I found in New York and London.

Thai: Any of the Thai Place restaurants.

Soul Food: Peach Tree Buffet on Eastwood Trafficway near the baseball stadium. They also have a fancy Peach Tree Restaurant near 18th & Vine.

Chicken, pork chops, catfish, etc: Stroud’s has great family style food. The original location is closed, but the one north of the River is in a wonderful old manor. The oldest dinning room dates from 1829.

Keith

When I lived in KC I took my visiting parents to the Steamship Arabia exhibit in the City Market. They loved it. I thought it was ok. I second the suggestion to visit the Liberty Memorial and I like Union Station also.

Even though it is a chain, IMHO the McCormicks and Schmick's at the Plaza is the best one of all the locations I have been to. Sit on the patio and look out over some of the best people watching in the midwest. I love going there for lunch and having oysters and disco lemonade.

KC's night life is great. On the plaza I like O'Dowd's Little Dublin. There are some other happening places like Harry's Supper Club in City Market and the Cashew in Midtown. Generally Westport is for the younger crowd and stag/hen parties.

It will be hot in August!

I'm a KC native. Check out the American Jazz Museum in the 18th and Vine area. Catch some dinner at the Peachtree, and then go back for a listen at The Blue Room. If you have time, also stop in the Negro Leagues Baseball Museum. Lots of great history there.

Where are you staying? The Plaza is nice, but so are some of the hotels near Crown Center/Union Station. If you have a car, it shouldn't be a problem. Benton's Steak & Chop House a top the Westin Crown Center Hotel has excellent views of the downtown skyline and a really nice atmosphere. They have a new chef who is getting good reviews - try their tornados of beef - it's to die for! Be prepared to pay about $100 for a dinner for two.

Also, West Side Story is playing during the time of your visit at the outdoor Starlight Theater. Shows usually start late, around 8:30 pm, so might be a nice way to round out a day.

If you are into beer, you might consider a tour of Boulevard Brewing Company on Southwest Trafficway. I recently took the tour and it is pretty impressive, plus you get to sample all of their varieties at the end! (Warning: cops do park right outside, so don't overindulge.)

If you want to get outside the city for a day, take a short one hour trip north to Weston. It's a quaint little town with lots of antique shops, great restaurants and wineries.

I also recommend dining at Blue Bird Bistro, 1700 Summit St., they grow all their own produce in a garden across the street! They serve breakfast, lunch and dinner.

LMK if you have any other questions...

If you are still checking this post, you mentioned liking museums AND trains...so second (or third or fourth or whatever point it is) going to Union Station.

It's beautifully restored, and pop downstairs for the train museum! I had never been and recently had a visitor who was a big train buff. It is small, but really well done and interesting.

As mentioned, the 18th and Vine museums are really interesting and the Peachtree just a block away is wonderful...great fried chicken, catfish, and sweet potato rolls!

Thanks for all of the great ideas. If anyone has any more, please let me know before the end of this week, as we will be going on Saturday, 8/4.

You've got many good suggestions. You indicate you like art, too bad you'll miss First Friday in the Crossroad's District by one day. All the galleries stay open to exhibit art work with food - drink - music. The new wing at the Nelson is incredible, especially for a town the size of KC.

I'll throw in Carmen's in Brookside - very good Italian food. Pierpont's in Union Station for steak. Oklahoma Joe's in KCK for bbq. Duomo in Brookside for sushi. Pine and Bamboo Garden in Shawnee Mission for Chinese.

Thanks go to everyone who responded. My brother and I had a great time in KC. There was plenty to do, and some great eating too.

Among the places we visited was The Truman Presidential Library and Museuam, The Truman House, The Truman Farm, The Kansas City Zoo, The 18th & Vine Museums - American Jazz Museum and Negro Leagues Baseball Museum, The 1950's All-Electric House, The National Agricultural Center and Hall of Fame, National Frontier Trails Museum, WWI Memorial/Museum and the Nelson-Atkins Museum of Art.

We had some great meals too. We tried both Gates and Arthur Bryant's for BBQ. Not to start any arguments, but we definitely would recommend Gates over Bryant's, both for taste and service.

We also had some great pizza at Minsky's Pizza, some great steaks at Hereford House, some great Italian at Figlio Italian Restaurant and Bar and another great pizza at T-Rex Cafe' at Legends in Kansas. That place was pretty cool. We also had lunch at Fritz's Railroad Restaurant in the Crown Center. If you have not been there, you have to go. Their method of food delivery to the tables is awesome. The food was good too.

The other place we ate at was George Brett's, though I would not recommend this place. The service was lousy.