Thank you for the clarfication. It seems this isn't documented and a very strange way of doing this since most API calls for history start at a value and return the future but this seem to be backwards. Doing some tests, my full history of an account is 309 ops.

Returns the two most recent ops.

steem.api.getAccountHistory(username, 309, 1)

Returns the first user op.

steem.api.getAccountHistory(username, 1, 1)

I think this can be closed as a bug and then moved to a documentation request on that method since it isn't really noted the from and limit goes backwards and not forwards.