Traveling with 5 months old to DC - Things to consider

They allow if you have a baby/toddler..some time they may ask you to taste it or for they may test it using some chemicals. I travelled FL and carried two water bottle for DD.

 

Don't ask while checking the bag..they says that security will not allow. It happens with us while going...we threw everything but by mistake left one yogurt pack and bottled water in stroller. When we were going for security asked one cop and he said just tell them it's for baby..Since yogurt was packed they didn't check (you will need take that out and put in separate basket ) and asked my DH to taste water.

 

Just my $0.02:

1) The weather is becoming awfully hot and humid now, pretty much like Chennai. Plan to keep outdoor trips short and carry water.
2) Parking around the National Mall is always a nuisance, and is even worse on the long weekend. We usually park in private garages a few blocks away and walk but this will be more difficult with a baby.
3) Metro can be an option but you will still have to walk. The weekend schedules are also slow, but may be better due to the holiday.
4) The National Zoo is a nice place to spend a day, but the parking fills up pretty quickly. It is however close to the Red Line metro.
5) My parents do the hop-on hop-off bus which goes to most of the major attractions. This is a convenient way to sight see. The distances are much longer than they seem for walking.
6) Food options on the Mall are not great, especially for vegetarians. One of the better places is the Mitsitam Cafe in the Native American museum.
The July 4th fireworks at the Washington monument are definitely worth watching.
Have a nice trip!