Could be this:

If it's dead, there shouldn't be too much to worry about :-)) Looks like a common garter snake to me and those are found everywhere across the US. And are harmless.

You need a banana for reference.

It was probably 8cm long.

Sammy - now that looks scary. Time to put some lime around the house to keep away the snakes.

Lime? Thats new for me! Just calcium carbonate powdered? Will pelletized work?

Snakes are our friends. They eat insects, and as they get larger they eat mice, voles, moles, etc.

While there are poisonous snakes in most areas of the US, the odds are that the snake you see will be a garter snake like you have found a rat snake, black racer, etc. If you are lucky you will see brown earth snakes or rough green snake.

http://www.defenders.org/snakes/basic-facts

https://www.google.com/search?q=pictures+of+common+snakes+in+your+garden&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwijkfWsrsTWAhXEKyYKHQyODMEQsAQIJQ&biw=1366&bih=640#imgrc=F_jTdtnvOyAnQM:

It does look like Storeria dekayi, brown snake. They're really common, probably more common than garter snakes, and there are lots of them around in cities and suburbs. Completely harmless, eats slugs and other pests, couldn't bite you if it tried.

Some of them are just plain light brown and some of them have a little bit of a pattern on them, and sometimes people panic when they see the patterned ones thinking they're copperheads. They like to hang out under rock or wood piles, under flower pots, etc.

https://www.livescience.com/53580-brown-snakes.html

Thank you all for your re-assurances :) Yes I have heard that if you put dry lime (Baseball field marker) around your house it will keep snakes away. Personally not tried it but planning to. And I do agree snakes are there to keep away pests but the family panics seeing this.

parsley..how can we make sure it is not a copperhead? I have pine-needles on a slope in my back-yard, so I just want to make sure this is a harmless snake.

The triangle head of venom is unmistakeable for the most part. The glands that hold the venom near the fangs is why. Google it and make yourself aware before you hurt yourself or worse, some beneficial creature.

Agree with trickyputt. Familiarize your family with the visual characteristics of poisonous snakes and you should be good to go. One good way to make sure it is not a copperhead is to use Google Images to find pictures of copperheads. Yours is clearly not a copperhead. In addition it is good to know what activity you can get away with when you see a snake. Viper type snakes coil up, strike, and release to attack their prey. They need to be coiled up before they can strike. They do not need to be coiled to bite, but in order to lash out at prey, then need to coil. Some other snakes, coral snakes for example, do not coil and do not strike like vipers. They need to bite and chew on their prey.

Side note: I started living in rural areas about 5 years ago. The first night staying in a friend's mobile home I saw a huge rattler. It was at night and with a flashlight, they have a very weird glow to them. I did not approach. After I moved to my own house I was walking my dog one night. She is blind and is very well coordinated. I noticed she seemed to briefly get tangled up in something as we walked along the street, so I investigated. It was a coral snake (red on yellow) about a foot long. Got a shovel from a neighbor and killed that one. Then just this past weekend I saw about a 2-3 ft black snake on my front walk. I approached to get it to move away from the door. It easily scooted/slithered into some taller grass in front.