An attempt to take New York would have to go through coastal defenses, which would at least delay the Germans a bit. Then they have to face urban fighting because the US isn't going to give up New York without a fight. If you want a place where quality mattering is massively reduced, urban fighting is it.
In 1898 the coastal defences of the US, while they do exist, are not very extensive. Here's the New York approaches:
Long Island Sound
Fort Griswold was an old Revolutionary War fort with smoothbores etc.
Fort Trumble was an old first system fort, placed under Fort HG Wright.
Fort H.G. Wright was commenced 1898:
1. Battery Butterfield (2x 12”) – 1901
2. Battery Barlow (2x 10”) – 1901
3. Battery Dutton (3x 6”) – 1901
4. Battery Hoffman (2x 3”) – 1904
5. Battery Hamilton (2x 6”) – 1905
6. Battery Hopcock (2x 3”) – 1905
7. Battery Marcy (2x 6”) – 1906
Fort Mansfield was commenced in 1898:
1. Battery Wooster (2x 8”) – 1901
2. Battery Crawford (2x 5”) – 1901
3. Battery Connell (2x 5”) – 1901
Fort Michie on Great Gull Island was commenced 1897:
1. Battery Palmer (2x 12”) – 1900
2. Battery North (2x 10”) – 1900
3. Battery Pasco (2x 3”) – 1905
4. Battery Benjamin (2x 6”) – 1908
5. Battery Maitland (2x 6”) – 1908
Fort Terry on Plum Island was commenced 1898:
1. Battery Steele (2x 10”) – 1900
2. Battery Kelly (2x 5”) – 1900
3. Battery Stoneman (8x 12” Mor) – 1901
4. Battery Bradford (2x 6”) – 1901
5. Battery Dimick (2x 6”) – 1905
6. Battery Dalliba (2x 3”) – 1905
7. Battery Greble (2x 3”) – 1905
8. Battery Campbell (2x 3”) – 1905
9. Battery Floyd (2x 6”) – 1906
10. Battery Hagner (2x 3”) – 1906
11. Battery Eldridge (2x 3”) – 1906
Fort Tyler on Gardiner’s Point Island was commenced, but never completed. As an expedient a 2x 8” Rodman battery was built here.
Eastern New York (via Long Island Sound)
Fort Schuyler was an old third system fort, which they started to modernise in 1896:
1. Battery Hazzard (2x 10”) – 1898 (commenced 1896)
2. Battery Gansevoort(2x 12”) – 1900
3. Battery Bell (2x 5”) – 1900
4. Battery Beecher (2x 3”) – 1900
Fort Slocum on David’s Island was commenced 1892:
1. Battery Haskin and Battery Overton (16x 12” Mor) – 1897 (commenced 1892)
2. Battery Practice (2x 8” Rodman smoothbores) – 1896
3. Battery Fraser (2x 5”) – 1901
4. Battery Kinney (2x 6”) – 1904
Fort Totten was a third system fort modernised:
1. Battery Graham (2x 10”) – 1897 (started 1896)
2. Battery Sumner (2x 8”) – 1899
3. Battery Stuart (2x 5”) – 1899
4. Battery King (8x 12” Mor) – 1900
5. Battery Mahan (2x 12”) – 1900
6. Battery Baker (2x 3”) – 1900
7. Battery Burnes (2x 3”) – 1904
Southern New York
Fort Jay is a disused first system fort.
Fort Lafayette is a disused second system fort.
Fort Tomkins is a disused second system fort.
Fort Hancock on Sandy Hook:
1. Battery Dynamite (1x 8” and 2x 15” Air-Torpedo launchers) – 1896
2. Battery Potter (2x 12” on gun-lifts) – 1898 (finished building in 1894)
3. Battery McCook and Battery Reyonds (16x 12” Mor) – 1898 (finished building in 1894)
4. Battery Granger (2x 10”) – 1898 (commenced 1896)
5. Battery Engle (1x 5”) – 1898 (started 1897)
6. Battery Alexander (2x 12”) – 1899
7. Battery Bloomfield (2x 12”) – 1899
8. Battery Halleck (3x 10”) – 1900 (commenced 1896)
9. Battery Peck (2x 6”) – 1903
10. Battery Urmston (6x 3”) – 1903
11. Battery Richardson (2x 12”) – 1904
12. Battery Morris (4x 3”) – 1904
13. Battery Gunnison (2x 6”) – 1905
Fort Hamilton has:
1. Battery Spear (3x 10”) – 1898
2. Battery Gilmore (4x 10”) – 1899
3. Battery Griffin (2x 4.72”) – 1899 (expanded with 2 more 3” in 1902, then another 2x 3” in 1903)
4. Battery Doubleday (2x 12”) – 1900
5. Battery Neary (2x 12”) – 1900
6. Battery Piper (8x 12” Mor) – 1901
7. Battery Harvey Brown (2x 12”) – 1902
8. Battery Johnston (2x 6”) – 1902
9. Battery Burke (4x 6”) – 1903
10. Battery Livingstone (4x 6”) – 1905
11. Battery Mendenhall (4x 6”) – 1905
Fort Wadsworth has:
1. Battery Upton (2x 10”) – 1897 (building completed 1895)
2. Battery Duane (5x 8”) – 1897 (commenced 1895, completed 1897)
3. Battery Barbour (2x 4.72” and 2x 6”) – 1898 (commenced 1898)
4. Battery Hudson (2x 12”) – 1899
5. Battery Richmond (2x 12”) – 1899
6. Battery Barry (2x 10”) – 1899
7. Battery Bacon (2x 3”) – 1899
8. Battery Mills (2x 6”) – 1900
9. Battery Ayres (2x 12”) – 1901
10. Battery Turnbull (6x 3”) – 1903
11. Battery Dix (2x 12”) – 1904
12. Battery Catlin (6x 3”) – 1904
So the eastern approach has 4 10" and 2 8" guns, along with 16 12" mortars. The southern approach has more at 7 10" and 2 12" and 6 8", along with 1 5", 2 4.72", 2 6" and 16 12" mortars.
Neither of these is anything like what the US considered it actually needed, as you can see from all the forts that were still being built.
Of course, the Germans don't have to ram themselves into the most prepared defences they can find. Here's the coastal forts protecting Philadelphia:
Delaware River
Fort Delaware was a third system fort on Pea Patch Island modernised thus:
1. Battery Dodd (2x 4.72”) – 1899 (commenced 1898)
2. Battery Torbet (2x 12”) – 1901 (commenced 1894, complete 1900)
3. Battery Alburtis (2x 3”) – 1901
4. Battery Allen (2x 3”) – 1901
5. Battery Hentig (2x 3”) – 1901
Fort DuPont started in 1897:
1. Battery Read (2x 12”) – 1899 (commenced 1898, simple barbette mount)
2. Battery Gibson (2x 8”) – 1899
3. Battery Rodney and Battery Best (16x 12” Mor) – 1900
4. Battery Richie (2x 5”) – 1900
5. Battery Elder (2x 3”) – 1904
Fort Mott is the same:
1. Battery Arnold (3x 12”) – 1899 (commenced 1896)
2. Battery Harker (3x 10”) – 1899 (commenced 1896)
3. Battery Krayenbuhl (2x 5”) – 1900 (commenced 1896)
4. Battery Gregg (2x 5”) – 1901
5. Battery Edwards (2x 3”) – 1902
So nothing in 1898.
And the Washington approaches:
Potomac River
Fort Hunt
1. Battery Mount Vernon (3x 8”) – 1898
2. Battery Porter (1x 5”) – 1901
3. Battery Robinson (1x 5”) – 1901
4. Battery Sater (3x 3”) – 1904
Fort Washington is the old fort, modernised as:
1. Battery Water (1x 10”) – 1898 (simple barbette hastily made)
2. Battery Decatur (2x 10”) – 1899
3. Battery Emory (2x 10”) – 1899
4. Battery Humphreys (2x 10”) – 1899
5. Battery White (2x 4”) – 1899
6. Battery Meigs (8x 12” Mor) – 1902
7. Battery Wilkin (2x 6”) – 1902
8. Battery Smith (2x 3”) – 1903
9. Battery Many (2x 3”) – 1905
Chesapeake Bay
Fort Monroe is an old fort modernised as:
1. Battery Humphreys (1x 10”) – 1897
2. Battery Bomford (2x 10”) – 1897
3. Battery Anderson and Battery Ruggles (16x 12” Mor) – 1898 (commenced 1896)
4. Battery Barber (1x 8”) – 1898 (simple barbette mounts)
5. Battery Parapet (4x 8”) – 1898 (barbette)
6. Battery Gatewood (4x 4.7”) – 1898
7. Battery Eustis (2x 10”) – 1901
8. Battery Church (2x 10”) – 1901
9. Battery Irwin (4x 3”) – 1903
10. Battery DeRussy (3x 12”) – 1904
11. Battery Montgomery (2x 6”) – 1904
12. Battery Parrott (2x 12”) – 1906
Fort Wool is opposite and similar:
1. Battery Hindman (2x 3”) – 1905
2. Battery Lee (4x 3”) – 1905
3. Battery Claiborne (2x 6”) – 1908
4. Battery Dyer (2x 6”) – 1908
5. Battery Gates (2x 6”) – 1908
If Fort Monroe can be run - not as hard as it may sound, it has three 10" guns, 5 8" guns and some mortars in place - then all that's protecting Washington is a pair of small batteries.
Note the main lesson here - the US was frantically building
lots of naval defences. They felt they needed them, and they did not yet have them; if they did not need them, they wasted a vast amount of money, while if they did need them then they don't have them yet and are vulnerable.