I don't know about jQuery but in general terms I can think of a few alternatives.

 1. Use [**isometric tiles**](http://www.miniwizardstudios.com/iso-tiles.asp) to create the background. It's very similar to creating a top-down tile based map but with tiles being offset a little. You can find more information [*here*](http://fivedots.coe.psu.ac.th/~ad/jg/ch064/ch6-4.pdf). Also check [this answer](https://gamedev.stackexchange.com/a/22279/11686) for a side-by-side comparison between isometric and top-down.

 ![enter image description here][1]

 2. Turn a top-down background into isometric by **rotating 45º and compressing it vertically**, either in code or in some [image manipulation software](http://www.gimp.org/).

 ![enter image description here][2]

 3. Probably not applicable here but in a 3D API you can also get an isometric view of the world by setting an **orthographic projection** and positioning the camera at the correct angle.

 [1]: https://i.sstatic.net/fFspT.png
 [2]: https://i.sstatic.net/JFWr4.png