All 3 Uses of

accord
in
Selected Tales, by Poe

It was the manner in which all this, and much more, was said—it was the apparent heart that went with his request—which allowed me no room for hesitation; and I accordingly obeyed forthwith what I still considered a very singular summons.†
Scene 3 *

accordingly = in keeping with or in agreement with what was just stated

Dropping of its own accord upon his exit (or perhaps purposely closed), it had become fastened by the spring; and it was the retention of this spring which had been mistaken by the police for that of the nail,—farther inquiry being thus considered unnecessary.†
Scene 4 *

own accord = own mind -- voluntarily (without anyone asking)

"The description of the digits," said I, as I made an end of reading, "is in exact accordance with this drawing.†
Scene 4

accordance = keeping with; or agreement with

Definitions:

(1) (accord as in: according to, or in accord with)
in keeping with; or in agreement/harmony/unity with
This meaning of accord is often seen in the form according to or accordingly where it can take on more specific meanings. For example:
- "According to Kim, ..." -- as stated by
- "To each according to her ability." -- based upon
- "Points are scored according to how well they perform." -- depending upon
- "The dose is calculated according to body weight." -- in proportion to
- "We got a flat tire. Accordingly, I pulled to the side of the road." -- because of what was just said; or as a result
(2) (accord as in: reached an accord)
an agreement

In this sense, accord can refer to a formal agreement (such as one written between two countries) or an informal agreement (such as an unvoiced consensus about what should be done).
(3) (accord as in: done of her own accord)
mind

This sense of accord is typically seen in the form own accord or one accord.
(4) (accord as in: accord her the respect deserved)
to give someone special treatment -- especially respect