New Macbook Pro with old ACD LCD Monitor
Get an adapter that goes from USB-C to Dual-Link DVI.
Get an adapter that goes from USB-C to (Mini)DisplayPort. Get a second adapter that goes from (Mini)DisplayPort to Dual-Link DVI. Daisy-chain them.
Note: Beware DVI adapters that do not specify dual-link DVI and that are not explicitly advertised as supporting a resolution of 2560 x 1600 pixels. Most inexpensive DVI adapters are single-link devices that cannot support the 30" ACD's resolution.