delivered the opinion of the court:
The contention of the plaintiff in error in this case is, that, when she purchased the west 15.2 feet of lot 8 and the east 14.8 feet of lot'9, being a lot 30 feet wide, from Frederick Sulzer in his lifetime, Frederick Sulzer agreed to convey and dedicate the east 31.8 feet of lot 10. and the west 30.2 feet of lot 9, being a strip of ground 62 feet wide, to the city of Chi - cago as a street, and to extend such street north as far as *92Cullom avenue through the property then unsubdivided. It is not claimed that the agreement thus alleged to have been made was a written agreement. It is admitted that it was a mere verbal agreement, said to have been made between Frederick Sulzer and plaintiff in error some ten days or two weeks, or thereabouts, prior to the execution of the written contract, executed between said parties ón December 7, 1891.
It is well settled “that a written contract, unambiguous in its terms, cannot be varied, contradicted or modified by parol evidence of anything that occurred at or prior to the time when such written contract was executed.” (11 Am. & Eng. Ency. of Law,—2d ed.—p. 548).
In Telluride Power Co. v. Crane Co. 208 Ill. 218, we said (p. 226) : “The rule is, that when the writings show, upon inspection, a complete legal obligation, without any uncertainty or ambiguity as to the object and extent of the engagement, it is conclusively presumed that the whole agreement of the parties was included in the writings.”
“A written contract, if unambiguous in its terms, can not be varied, contradicted or modified by parol evidence of conversations relating to the subject matter of the contract, which occurred between the contracting parties before the execution of the contract.” (Town of Kane v. Farrelly, 192 Ill. 521). Nor can a sealed executory contract be altered, changed or modified by parol agreement. (Alschuler v. Schiff, 164 Ill. 298).
The written contract executed between plaintiff in error and Frederick Sulzer on December 7, 1891, is presumed to have embodied the whole of their agreement, and all previous verbal arrangements, if any there were, were merged into such written contract. The written contract of December 7, 1891, is silent as to the conveyance or dedication of any parts of lots 9 and 10, or of the ground lying north thereof for street purposes. The contention of the plaintiff in error is, that there was a verbal contract between her and Frederick Sulzer for the purchase of the 30 feet bought by her, and *93that, as a part of that verbal contract, Frederick Sulzer agreed to open a street west of the 30 feet purchased by her; and it is said that, in consideration of the agreement so to open said street, plaintiff in error was to pave the part of Berteau avenue lying south of the part, so. to be dedicated as a street, but there is nothing in the written contract as to the agreement so alleged to have been verbally made between the parties. As plaintiff in error and Frederick Sulzer put their contract in writing, the writing must control. Parol evidence was inadmissible to change its terms in the manner stated. The testimony as to the alleged oral contract was admitted subject to objection, and it is evident that the chancellor below properly regarded it as incompetent and refused to consider it in making his decree.
The plat of Frederick Sulzer’s addition, upon which are noted lots 8 and 9, parts of which plaintiff in error purchased, was introduced in evidence by plaintiff in error upon the hearing below, and its introduction was not objected to by the defendants in error. The plat of the addition, therefore, must be regarded as a valid map or plat of the property in question, as it is so treated by both parties. This plat shows upon its face lots 8, 9, 10 and 11, each being 45 feet wide, as having been laid off by Frederick Sulzer, the maker of the plat, and the owner of the property sold to plaintiff in error. In the written contract of December, 1891, signed by Frederick Sulzer and the plaintiff in error, and also in the deed of April 3, 1899, signed by the defendants in error, and accepted by plaintiff in error, the property conveyed is described as being certain designated parts of lots 8 and 9 in said Sulzer’s addition, as described in the statement preceding this opinion. “Where a deed refers to a plat or subdivision, the particulars shown upon such plat or subdivision are as much a part of the deed as though they were recited in it.” (Henderson v. Hatterman, 146 Ill. 555; Smith v. Young, 160 id. 153; Louisville and Nashville Railroad Co. v. Koelle, 104 id. 455; Simpson v. Mikkelsen, 196 id. 575; *94 Thompson v. Maloney, 199 id. 276). It thus appears that the contract, signed by plaintiff in error, and the deed, made to her and accepted by her, refer to lot 9 as the same is indicated upon the plat to Sulzer’s addition. Upon that plat lot 9 is a lot 45 feet wide, and contains not only the east 14.8 feet conveyed to plaintiff in error, but also the west 30.2 feet. Therefore, plaintiff in error is estopped from claiming that the west 30.2 feet of lot 9 is part of a street agreed to be dedicated, when, by the .description in her deed, she recognizes it as a part of lot 9, as designated upon the plat of Sulzer’s addition, to-wit, a lot 45 feet wide not abutting upon a street, and not connected ih any way with a street.
Counsel for plaintiff in error refer to many cases, which hold that a dedication may be evidenced by acts and declarations, as well as by grant or other written instrument, and they also refer to several cases, which state that a map is not-essential to the validity of the dedication. Relying upon these cases, plaintiff in error insists that, when Frederick Sulzer took the plat of Sulzer’s addition and indicated thereon with his finger the parts of lots 9 and 10 which he would dedicate as a street, and when he stepped off upon the ground the space 62 feet wide to be dedicated as' a street, such acts on his part amounted to a dedication. The cases referred to, however, do not sustain the contention óf the plaintiff in error. In most of the cases it was shown that sales were made according to some plat, which, though not valid as a statutory plat, yet was of such a character as to make the act of selling lots, designated upon the same and abutting upon streets, amount to a common law dedication of such lots. Even in cases where no map was shown to have been made, it will appear from an examination that a survey of the ground had been made, and that lots were sold in reference to such survey. 3
In Godfrey v. City of Alton, 12 Ill. 29, it appeared that a survey had been made and ground had been laid off for public use as a street or landing, and that sales had been *95made in reference thereto, and, in view of these circumstances, it was there held that there was a dedication of such ground to the public. So, in Zearing v. Raber, 74 Ill. 409, it appeared that the owner of lots had the same platted showing a street, and sold a part of the same with reference to such street. In Alden Coal Co. v. Challis, 200 Ill. 222, while it appeared that no plat had been made, yet the proof showed that a town site had been staked out, and people had been invited to locate thereon, and houses had been built, and streets improved, and residences and business sites had been leased; and, under such circumstances, it was held that the owner of the ground was estopped from denying the dedication of the streets to the public, and that the making of a map of the town site was not necessary to the validity of the dedication. But, in the case at bar, no map or plat was made showing a street at the point where the land is said to have been dedicated, nor was any survey made of the ground for the purpose of laying out a street. On the contrary, the oral testimony introduced contradicts the showing upon the face of the map. The map of Sulzer’s addition, upon its face, shows that lots 8, 9, 10 and 11 were inside lots and did not abut upon any street. The parol testimony, introduced by plaintiff in error, had a tendency to contradict the showing of the very map, which plaintiff in error herself introduced in evidence; and was, therefore, incompetent.
In addition to what has been said, the main witnesses, by whom it was sought to prove the verbal agreement in question, were plaintiff in error, the complainant in the suit, and her sister-in-law, Mrs. Schumaker. Plaintiff in error filed a bill against the defendants in error as heirs-at-law of Frederick Sulzer, deceased. She was, therefore, an incompetent witness under section 2 of chapter 51 of the Revised Statutes in regard to evidence, which provides that no party to any civil action, suit or proceeding, shall be allowed to testify therein of his own motion, or in his own behalf, when any adverse party sues or defends as heir, legatee or *96devisee of any deceased person, etc. (2 Starr & Curt. Ann. Stat.—2d ed.—p. 1824).
Mrs. Schumaker was also an incompetent witness, ^ because she was interested in having the street opened or dedicated, as the strip 62 feet wide, lay just east of the 30 feet purchased by her, and, if the same was dedicated as a street, it would inure to her benefit,"'as it would make her lot a corner lot. Said section 2 of the act in regard to evidence provides that no “person' directly interested in the event” of any civil action, suit or proceeding shall be allowed to testify when the adverse party defends as heir. .Mrs. Schumaker being incompetent as a witness because of her interest, her husband, Joseph W. Schumaker, was incompetent. (Treleaven v. Dixon, 119 Ill. 548; Way v. Harriman, 126 id. 132; Stodder v. Hoffman, 158 id. 486; Craig v. Miller, 133 id. 300; Crane v. Crane, 81 id. 165; Warrick v. Hull, 102 id. 280; Best v. Davis, 44 Ill. App. 624). The plaintiff in'' error, and Mrs. Schumaker, and her husband, are the only witnesses, who testified to the verbal arrangement said to have been made with Frederick Sulzer in his lifetime, and, their testimony being incompetent, there was no competent evidence establishing the verbal agreement alleged to have been made.
It also appears from the evidence that, at the time when the verbal agreement in question is alleged to have been made, Frederick Sulzer did not own the land lying north of the lots 8 and 9 here in controversy, and south of Cullom avenue. A verbal agreement by him to extend a street through land, which did not belong to him, and dedicate the same to the city, could not have been valid. The proof shows that the land lying north of lots 8 and 9 was not conveyed to the defendants in error until long after the death of Frederick Sulzer. ••
It is also contended by plaintiff in error that a certain endorsement upon a duplicate copy of the original agreement of December 7, 1891, was improperly admitted. This *97endorsement bears date April 19, 1899, and is as follows: “This contract performed by delivery of deed dated April 3, 1899, and mistake in description herein corrected by deed.— Julia Schneider, by Henry P. Kranz, her agent.” It is not necessary to discuss the question whether this endorsement was properly or improperly admitted, for the reason that the plaintiff in error could have suffered no injury from its admission. This is so, for the reason that the deed of April 3, 1899, recites upon its face that it was executed in pursuance of the contract of December 7, 1891. The Statute of Frauds was pleaded. The Statute of Frauds was properl}7 pleaded by the defendants in error in their answer to the bill, and, in view of what has already been said, we think that the statute was applicable to the present case.
For the reasons above stated, we are of the opinion that the decree of the circuit court in dismissing the bill was correct.
Accordingly, the decree of the circuit court is affirmed.
Decree affirmed.