CREATE TABLE table_203_674 (id DECIMAL, "name" TEXT, "mark" TEXT, "system" TEXT, "from" DECIMAL, "to" DECIMAL, "successor" TEXT, "notes" TEXT)

was the pennsylvania railroad under the prr or the rf & p ?
SELECT "system" FROM table_203_674 WHERE "name" = 'pennsylvania railroad'
SELECT "system" FROM "table_203_674" WHERE "name" = 'pennsylvania railroad'