Thanks all for the advice on the pigtails. And yep, the breaker is 15A. As for the light fixture, it hangs from two chains so the cord does not support any weight. When I went to HD, they suggested using the standard 16/2 lamp cord since it's brown and would blend in best with the brass fixture. It seemed fine as far as size and flexibility. But I wasn't sure if there was any reason that I should use something more "heavy-duty". Is there a specific insulation temperature rating I should be looking for? (The wire they gave me says 60 degrees Celsius on it).

The old chandelier only had two wires wired into the box and the new chandelier will wire into the same two wires. All the other wires are passing through and should not be messed with. Carefully inspect the two black wires from the new chandelier to see if they are exactly the same. Any difference, (ridges or stripes) means that it will likely be the white wire. Post the photos on here so that everyone can get a look at them.

I'm confused. You purchased a new what? Older lamps typically didn't have a ground but some had a polarized plug so that the exposed metal was at least connected to the grounded conductor. Now if you want to connect a ground, you have to be careful. If the current carrying wiring is connected to the exposed metal, you need to leave the ground alone. If it's connected only to the bulb sockets (typically the threaded part not the button in the middle) then the rest of the metal should be grounded.

2008 NEC 250.130 Equipment Grounding Conductor Connections. Equipment grounding conductor connections at the source of separately derived systems shall be made in accordance with 250.30(A)(1). Equipment grounding conductor connections at service equipment shall be made as indicated in 250.130(A) or (B). For replacement of non– grounding-type receptacles with grounding-type receptacles and for branch-circuit extensions only in existing installations that do not have an equipment grounding conductor in the branch circuit, connections shall be equipment grounding conductor in the branch circuit, connections shall be permitted as indicated in 250.130(C) (C) Nongrounding Receptacle Replacement or Branch Circuit Extensions. The equipment grounding conductor of a grounding-type receptacle or a branch-circuit extension shall be permitted to be connected to any of the following: (1) Any accessible point on the grounding electrode system as described in 250.50 (2) Any accessible point on the grounding electrode conductor (3) The equipment grounding terminal bar within the enclosure where the branch circuit for the receptacle or branch circuit originates (4) For grounded systems, the grounded service conductor within the service equipment enclosure (5) For ungrounded systems, the grounding terminal bar within the service equipment enclosure FPN: See 406.3(D) for the use of a ground-fault circuitinterrupting type of receptacle. 406.3 General Installation Requirements. Receptacle outlets shall be located in branch circuits in accordance with Part III of Article 210. General installation requirements shall be in accordance with 406.3(A) through (F). (D) Replacements. Replacement of receptacles shall comply with 406.3(D)(1), (D)(2), and (D)(3) as applicable. (1) Grounding-Type Receptacles. Where a grounding means exists in the receptacle enclosure or an equipment grounding conductor is installed in accordance with 250.130(C), grounding-type receptacles shall be used and shall be connected to the equipment grounding conductor in accordance with 406.3(C) or 250.130(C). (2) Ground-Fault Circuit Interrupters. Ground-fault circuit-interrupter protected receptacles shall be provided where replacements are made at receptacle outlets that are required to be so protected elsewhere in this Code. (3) Non–Grounding-Type Receptacles. Where attachment to an equipment grounding conductor does not exist in the receptacle enclosure, the installation shall comply with (D)(3)(a), (D)(3)(b), or (D)(3)(c). (a) A non–grounding-type receptacle(s) shall be permitted to be replaced with another non–grounding-type receptacle(s). (b) A non–grounding-type receptacle(s) shall be permitted to be replaced with a ground-fault circuit interruptertype of receptacle(s). These receptacles shall be marked "No Equipment Ground." An equipment grounding conductor shall not be connected from the ground-fault circuitinterrupter-type receptacle to any outlet supplied from the ground-fault circuit-interrupter receptacle. (c) A non–grounding-type receptacle(s) shall be permitted to be replaced with a grounding-type receptacle(s) where supplied through a ground-fault circuit interrupter. Grounding-type receptacles supplied through the groundfault circuit interrupter shall be marked "GFCI Protected" and "No Equipment Ground." An equipment grounding conductor shall not be connected between the groundingtype receptacles.